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GUDDEN'S    ATROPHY     METHOD:     AND    A 
'^  SUMMARY  OF   ITS   RESULTS 


BY 


E.  C.i^GUIN,  M.D. 

COXRESrONUING   MEMBER  OF  THE  "  VEREIN  FUR  INNERE  MBDICIN  "    OP  BERLIN 


[Reprinted  from  the  Archives  of  Medicine,  Vol.  x,  Nos.  2  and  3,  1883] 


G.    P.    PUTNAM'S    SONS 

NEW    YORK  :    27   &   29   WEST   23D   STREET 
LONDON  :    25    HENRIETTA   STREET,    COVENT  GARDEN 

1883 


^ 


T^AilT 


GUDDEN'S    ATROPHY  METHOD:    AND   A   SUM- 
MARY OF  ITS  RESULTS. 

By  E.  C.  SEGUIN,  M.D. 

MUCH  as  we  honor  the  discoverer  of  a  new  fact  of 
importance  or  of  a  series  of  facts,  we  owe  much 
more  to  him  who  places  at  our  disposal  a  new  method,  one 
sufficiently  tried  to  merit  adoption  at  our  hands.  A  method 
is  a  chapter  of  applied  logic,  pregnant  with  possible  results 
of  unknown  importance.  And  this  is  not  its  only  value, 
for,  as  a  part  of  the  logic  of  science,  it  also  serves  a  purpose 
in  scientific  speculation,  and  almost  inevitably  gives  rise 
to  new  ideas,  to  other  methods,  by  analogy  or  by  deduction. 

Gudden's  atrophy  method,  one  of  the  anatomical 
methods  applied  to  the  study  of  that  obscure  field  of  re- 
search— the  central  nervous  system, — lay  hidden,  most  un- 
fortunately, in  the  possession  of  its  originator  and  a  few 
pupils,  for  nearly  thirty  years,  and  even  since  its  publica- 
tion in  1872,  it  has  been  but  little  noticed  outside  of  a  very 
small  circle  of  neurologists.'  Yet,  I  think  that  the  follow- 
ing abstract  will  show  it  to  be  one  of  the  most  important 
and  promising  of  the  various  special  anatomical  methods.* 

From  1850  to  1852  Augustus  Waller  was  at  work  in 
Budge's  laboratory  at  Bonn,  perfecting  his  method  of  study- 
ing the  degeneration  of  severed  nerves.  The  facts  of  de- 
generation and  regeneration  after  nerve-section  had  been 
long  known,  but  it  remained  for  Waller  to   formulate  the 

*  In  the  most  recent  scientific  work  on  anatomy  (Burt  G.  Wilder  and  Gage, 
"Anatomical   Technology,"    New  York,    18S2),    containing  a  remarkably  full 
'bibliographical  index,  the  name  of  Gudden  does  not  appear. 

"  The  special  anatomical  methods  applied  to  the  study  of  the  central  nervous 

Reprinted  from  the  Archives  of  Medicine,  Vol.  x,  No.  2,  October,  1883. 


2  GUDDEN'S  ATROPHY  METHOD. 

law  under  which  the  degenerative  process  occurs.  In  his 
'' Noiivelle  m^thode  anatomique,''  Bonn,  1852,  he  gave  a 
full  summary  of  the  facts  and  laws  he  had  discovered,  and 
they  have  been  common  property  ever  since,  leading  to 
numerous  important  anatomical  and  pathological  discover- 
ies. The  doctrine  of  the  Wallerian  degeneration,  has,  I 
may  say,  been  a  valuable  instrument  in  our  hands  for  thirty 
years. 

At  the  very  same  time,  1849,  Gudden,  a  recent  graduate 
of  the  University  of  Berlin,  then  assistant  physician  in  the 
Siegburg  insane  asylum  under  the  celebrated  Jacobi,was  ex- 
perimenting upon  the  brains  of  animals  in  a  different,  yet 
correlative,  manner.  He  had  already  extirpated  eyes  of 
rabbits,  and  noted  the  atrophy  of  the  intracranial  optic  ap- 
paratus; he  already  knew  the  tractus  peduncularis  trans- 
versus,  and  many  of  his  subsequent  discoveries  were  half 
developed.*  This  was  done  in  ignorance  of  Waller's  work, 
and  partly  before  it  ;  certainly  long  before  Tiirck's  publica- 
tions on  secondary  degenerations. 

For  reasons  best  known  to  himself.  Professor  von  Gud- 
den did  not  publish  an  account  of  his  method  until  1870,^ 
although  his  principal  facts  and  laws  had  long  been  known 
to  him,  and  he  had  communicated  freely  with  friends  and 
assistants,  so  that  we  have  here  a  striking  example  of  the 
simultaneous  discovery  of  facts,  laws,  and  methods  which, 
applied  to  the  same  division  of  the  animal  frame,  are  in 
themselves  not  very  unlike,  and  in  their  results  are  logically 
united,  and,  indeed,  complementary  to  each  other. 

system  are  :  (a),  The  dissociation  or  dissection  of  fasciculi  in  partially  hardened 
specimens,  as  practised  by  older  anatomists,  by  Foville,  Gratiolet,  Broadbent, 
and  many  others  (nearly  disused);  (b),  the  Rolando-Stilling  method  of  series  of 
fine  sections  of  the  hardened  organs  ;  (c),  the  Wallerian  degeneration  in  ani- 
mals ;  (d),  the  Tiirck  secondary  degenerations  in  man  (and  in  animals);  (e), 
Flechsig's  method  of  determining  the  period  at  which  certain  systems  of  fibres 
in  the  foetus  acquire  myelin. 

'  Oral  communication  from  Prof.  v.  Gudden,  August  4,  1883. 

^  Experimentaluntersuchungen  iiber  das  peripherische  und  centrale  Nerven- 
system.      WesphaFs  Archiv,  Bd.  ii,  p.  693. 


E.    C.    SEGUIN.  3 

I  purpose  in  the  following  pages  to  enunciate  the  central 
principle  of  Gudden's  method,  and  then  to  analyze  his  pub- 
lications and  those  of  his  pupils,  more  or  less  in  chrono- 
logical order  with  reference  to  publication.  Besides  con- 
sulting these  publications,  I  have  had  the  advantages  of 
conversing  with  Prof.  Gudden  and  several  of  his  pupils, 
and  of  examining  the  specimens  proving  the  statements 
advanced  in  nearly  every  case. 

Principle  :  TJiat  by  experimenting  on  neivly-born  animals, 
especially  those  zvhich,  like  the  rabbit,  are  brought  forth  in  a 
sometvJiat  fcetal  state,  complete  atrophy  of  the  central  connec- 
tions of  a  nerve-trunk,  or  a  nerve-fasciculus,  or  a  nerve- 
centre,  is  obtained  by  operation.  The  central  {proximal) 
fibres  and  cells  are  destroyed,  ivJiile  the  peripheral  fibres,  if 
any,  undergo  the  Wallerian  degeneration. 

There  are  several  secondary  advantages  in  using  very 
young  animals;  they  (rabbits  at  least)  have  almost  no  hair; 
they  suffer  but  little  pain,  and  scarcely  struggle  under  the 
knife ;  they  bear  the  shock  of  incision  and  removal  of 
important  parts  of  the  central  nervous  system  wonderfully 
well ;  haemostasis  is  in  them  very  rapid  and  definite,  and 
the  process  of  repair  simple. 

For  operations  on  nerve-trunks,  almost  any  animal  can 
be  used.  For  experiments  on  intracranial  parts,  dogs  are 
objectionable  because  of  their  hard  craniums  ;  kittens  are 
intermediate  between  rabbits  and  dogs  in  this  respect,  but 
they  are  liable  to  suppuration,  and  the  mother  is  apt  to 
interfere  with  the  sutures. 

Most  operations  should  be  done  on  the  second  or  third 
day  of  life,  but  may  succeed  later;  still,  the  older  the 
animal  the  more  the  Wallerian  law  of  degeneration  in  one 
direction  (centrifugal  from  centre)  only  prevails. 

For   most    operations   on   the    olfactory  apparatus  it    is 


4  GUDDEN'S  ATROPHY  METHOD. 

necessary  to  wait  until  the  animal  (rabbit)  be  six  or  seven 
days  old,  in  order  to  give  time  for  the  ears  (hearing  and 
tactile  sense)  to  develop  sufficiently  to  enable  the  creature 
to  guide  itself  and  find  the  mother. 

For  operations  on  the  hypoglossal  and  vagus  nerves 
one  must  wait  still  longer,  from  the  second  to  the  sixth 
week/ 

The  various  operative  procedures  will  be  described  under 
the  several  heads  of  this  review,  but  it  is  well  to  state  here 
that  the  lesion  should  be  a  destructive  one ;  the  olfactory 
lobe  or  eyeball  must  be  removed,  or  in  the  case  of  nerves, 
their  central  ends  after  section  must  be  pulled  out  of  their 
bony  canals  with  good  forceps.  In  the  case  of  nerves  in 
newly-born  animals,  so  much  comes  away  by  this  method 
that  there  is  reason  to  believe  that  some  axis-cylinders  are 
broken  off  deep  in  the  nervous  centre  from  which  they 
spring. 

It  is  possible  that  some  of  Gudden's  operations  give 
results  as  much  by  degeneration  as  by  simple  atrophy  ;  in 
other  words,  that  his  and  Waller's  method  overlap  each 
other.  In  this  connection  let  me  say  that  the  histology  of 
the  early  period  of  Gudden's  atrophy  is  unknown,  which  is 
a  deplorable  hiatus  in  our  knowledge.  From  a  study  of 
this  point  we  may  learn  something  of  the  obscure  point 
referred  to,  viz.,  the  true  relation  between  the  two  methods, 
and  obtain  new  light  on  so-called  "  trophic  "  laws  of  the 
nervous  system. 

The  operated  animals  are  left  to  the  mother's  care,  and 
allowed  to  grow  from  six  to  twelve  weeks  ; ,  the  former 
period  being  quite  sufficient  for  most  experiments.  Indeed, 
Gudden  has  shown  ^  that  after  removal  of  one  eyeball  in 
dogs  one  day  old,  distinct  atrophy  of  the  optic  nerve  was 

'  Oral  communication  from  Prof.  v.  Gudden. 

'  Archiv  f.  Ophthalmologic,  Bd.  xxv,  Heft  4,  pp.  237-246,  1879. 


E.    C.    SEGUIN.  5 

visible  on  the  8th,  14th,  and  28th  days.  In  rabbits  a  dis- 
tinct atrophy  may  be  visible  in  36  hours  after  operation  on 
second  day/ 

During  this  period  of  preservation,  the  animals  should 
be  carefully  studied  as  to  their  functions,  with  especial 
reference  to  the  injured  apparatus,  and  compensatory  func- 
tions. By  doing  this  in  as  careful  a  manner  as  Munk  has 
done  for  his  cortex  experiments,  some  physiological  and 
psychological  knowledge  might  be  gained  from  each  series 
of  operations.  This  has  been  done,  but  not  as  fully  or 
exactly  as  should  be. 

After  the  animals  are  sacrificed,  the  affected  parts  should 
be  carefully  examined  for  asymmetry,  change  in  color  and 
consistence.  If  possible,  photographs  of  the  fresh  speci- 
mens should  be  taken,  and  careful  measurements  of  parts 
made.  The  organs  are  then  placed  in  a  solution  of 
bichromate  of  potassium,  or  of  osmic  acid,  for  hardening. 
When  this  is  complete  the  various  sections  necessary  to 
reveal  the  direction  and  extent  of  central  changes  are  made 
and  preserved  in  accordance  with  well-known  methods.  It 
is  often  desirable  to  have  complete  series  of  sections 
through  the  whole  organ  or  a  portion  of  it,  so  as  to  enable 
the  exact  extent  and  distribution  of  the  atrophy  to  be  fol- 
lowed. In  such  cases  the  use  of  Gudden's  microtome  is 
necessary.  The  sections  should  be  thin  enough  to  allow  of 
their  examination  by  |-  or  -|-  inch  objectives.  Usually  trans- 
sections  show  the  lesion  well,  but  in  some  cases  (olfactory 
part  of  anterior  commissure)  longitudinal  dextro-sinistral 
sections  are  necessary. 

The  condition  of  the  atrophied  centres  may  be  roughly 
stated  as  follows:  As  an  example,  after  extraction  of  the 
facial  nerve,  a  series  of  trans-sections  of  the  medulla  show 
simply  an  absence,   a  total  absence,   of  the  injured  nerve- 

^  Ibidejji,  Bd.  xxv,  Heft  i,  pp.  1-56. 


6  GUDDEN'S  ATROPHY  METHOD. 

trunk  in  its  course  through  the  medulla,  and  of  its  nucleus 
of  origin.  There  is,  architecturally  speaking,  a  virtual  void 
in  this  region,  which  is  filled  up  or  compensated  to  a  degree 
by  the  ingrowth  and  overcrowding  of  adjacent  normal 
parts.  There  are  no  exudations,  thickening  of  neuroglia, 
areas  of  disintegration,  etc.,  so  that  the  topographical  study 
of  the  sections  and  the  tracing  out  of  the  atrophy  are  not 
hindered  as  in  ordinary  pathological  specimens. 

RESULTS   OBTAINED    BY    GTIDDEN'S    METHOD. 

I  propose  mentioning  these  very  briefly  and  without 
criticism.  Many  of  the  questions  to  which  the  experiments 
relate  are  novel  and  intricate ;  further  researches  by  other 
methods  may  modify  the  views  held  by  Gudden  and  his 
pupils,  but  these  views  should  be  plainly  stated  so  as 
to  serve  as  data  for  other  observers.  Enough  will  be  found 
in  this  abstract  to  justify,  I  think,  the  statement  that  we 
already  owe  much  in  anatomy  and  physiology  to  this 
method,  and  that  it  offers  great  possibilities  for  the 
future. 

The  topics  will  be  considered  partially  in  chronological 
order. 

/, — Composition  and  connections  of  the  commissura  anterior 

cerebri. 

Von  Gudden  and  Ganser  have  been  able  to  resolve  these 
two  questions  in  greater  part  by  the  atrophy  method.  It 
has  long  been  known  that  the  c.  A.  consists  of  two  unequal 
fasciculi,  variable  in  different  animals,  and  these  Ganser 
calls  (i)  pars  temporalis;  (2)  pars  olfactoria.  In  general 
terms,  as  revealed  in  normal  sections,  the  p.  t.  is  very  much 
larger  in  man  and  in  monkeys,  while  in  lower  mammals, 
particularly  the  hedgehog,  mole,  and  rabbit,  the  p.  o.  is 
highly  developed  and  larger  than  the  p.  t. 


E.    C.    SEGUIN.  7 

1.  Pars  temporalis.  Von  Gudden,  in  1870/  published 
experiments  illustrating  the  nature  of  the  pars  temporalis. 

ExPT. — In  a  newly-born  rabbit  the  whole  upper  part  of  one 
cerebral  hemisphere  was  excised,  above  the  basal  ganglia. 
Autopsy  at  eight  weeks  showed  the  commissura  anterior  normal. 

ExPT. — In  another  rabbit  the  whole  of  one  hemisphere  was 
removed.  Seven  weeks  later  the  animal  was  killed,  and  sections 
of  the  (hardened)  brain  showed  complete  atrophy  of  the  commis- 
sura anterior.  The  external  capsule  was,  however,  preserved  in 
the  remaining  hemisphere. 

In  both  experiments  there  was  atrophy  of  the  corpus  callosum, 
complete  in  the  latter. 

Conclusions  :  the  temporal  division  of  the  C.  A.  is  a  true 
commissure,  as  is  also  the  corpus  callosum. 

The  external  capsule  has  no  direct  connection  w^ith  the 
C.  A. 

These  experimental  results  have  been  confirmed  by 
Ganser.  The  conclusions  are,  moreover,  supported  and  ex- 
tended by  the  result  of  the  careful  study  of  complete  series 
of  brain  sections  of  man,  monkey,  and  lower  mammals, 
made  by  Ganser.''  The  sections  were  transverse  and 
horizontal,  and  in  them  the  course  of  the  C.  A.  (its  pars 
temporalis)  was  always  distinctly  into  the  temporal  lobe,  be- 
yond the  nucleus  amygdalus.  No  fasciculi  going  to  other 
parts  of  brain  (occipital  lobes,  Meynert  et  al.)  could  be 
discovered. 

2.  Pars  olfactoria.  Von  Gudden  experimented  on  this 
also,  but  his  conclusions  were  invalidated  by  a  source 
of  error  discovered  later  on.  It  is  to  Ganser  (op.  cit.) 
that  we  owe  the  absolute  demonstration  of  its  true  nature 
and  distribution  by   means  of  von  Gudden's  method. 

*  Experimentaluntersuchungen  uber  das  peripherische  und  centrale  Nerven- 
system.      Westphal' s  Archiv,  Bd.  ii,  p.  693,  experiments  v  and  vi. 

"  S.  Ganser  :  Ueber  die  vordere  Commissur  der  Saugethiere.  Westphal' s 
Archiv,  Bd.  ix.  Heft  2,  1878. 


8  GUD DEN'S  ATROPHY  METHOD. 

ExpT. — The  brain  of  two  rabbits  formerly  operated  by  von 
Gudden  were  cut  into  complete  series  of  horizontal  and  transverse 
sections.  The  injury  consisted  in  destruction  of  the  left  tractus 
olfactorious  and  frontal  part  of  lobus  pyriformis  with  a  por- 
tion of  adjacent  (dorsal)  frontal  lobe.  The  left  bulbus  olfac- 
torius  (lobus  olf.)  was  very  much  atrophied.  In  both  sets  of  sec- 
tions (the  horizontal  best  adapted)  there  was  complete  absence  of 
the  olfactory  division  of  the  c.  a. 

ExPT. — Two  other  rabbits  from  whom  von  Gudden  had  re- 
moved one  of  the  bulbi  olfactorii.  These  brains  were  shrunken 
and  overhardened,  yet  fairly  good  sections  were  obtained,  enough 
to  show  that  in  these  two  cases  also  there  was  complete  atrophy  of 
the  p.  ol.  of  the  c.  a. 

Conclusions :  the  pars  olfactoria  of  the  C.  A.  is  also  a 
true  commissure,  and  unites  the  two  bulbi  olfactorii. 

Thus,  by  a  few  simple  experiments  and  careful  observa- 
tions (objectively  carried  out)  of  preparations,  is  that 
fanciful  fabric,  Meynert's  olfactory  chiasma  overturned. 

//. — Commissiira  inferior  cerebri. 

Almost  from  his  earliest  experiments  on  the  optic  appara- 
tus, von  Gudden  had  observed  that  after  removal  of  both 
eyeballs,  a  portion  of  the  chiasma  and  of  the  optic  tracts 
did  not  undergo  atrophy.  In  his  first  published  accounts  ' 
of  the  structure  of  the  optic  nerves,  etc.,  he  formulated  this 
observation  by  naming  the  surviving  or  non-atrophied 
nervous  band,  commissura  inferior  cerebri,  and  expressed 
the  opinion  that  it  was  a  commissure  between  the  thalami. 
In  the  first  of  his  series  of  contributions  "^  in  Grczfe's  Archiv, 
these  preliminary  demonstrations  are  repeated.  In  the 
third  contribution, Mn  reply  to  certain  statements  of  Michel, 

'  Experimentaluntersuchungen  iiber  das  peripherische  und  centrale  Nerven- 
system.      WestphaVs  Archiv,  Ed.  ii,  p.  693  (1S70). 

Sitzung  der  viii  Versammlung  der  Schweitzarischen  Irrenserzte  (Sept.,  1872), 
abstract  in  Psychiatrische  Zeitschrift,  Bd,  xxx,  p.  135. 

^  Ueber  die  Kreuzung  der  Fasern  im  Chiasma  Nervorum  Opticorum.  Archiv 
f.  Ophthalmologie,  Bd.  xx,  Heft  2.  pp.  249-268,  1S74; 

The  second  contribution  is  in  Bd.  xxi,  Heft  3,  pp.  199-205,  1875. 

^  Idem,  Bd.  xxv,  Heft  i,  pp.  1-56,  1879. 


E.    C.    SEGUIN.  9- 

he  insists  upon  the  distinction  between  this  fascicuhis 
and  the  one  known  as  Meynert's  commissure,  which  is 
distinctly  dorsal  of  the  chiasma,  and  separated  from  it.  The 
commissura  inferior,  on  the  contrary,  is  mingled  with  the 
tractus  opticus  and  can  only  be  discerned  by  excluding  the 
fibres  of  the  latter,  which  is  easily  done  by  removal  of  both 
eyeballs  in  the  young  animals,  thus  producing  atrophy  of 
all  the  truly  optic  fasciculi. 

Sometimes  in  the  rabbit,  dog,  and  cat,  a  slight  depression 
in  the  caudal-ventral  aspect  of  the  chiasm  suggests  its 
limits. 

In  trans-sections  of  rabbits'  tractus  opticus  no  special  limit 
is  discernible;  but  it  is  noticed  that  while  the  optic  fibres 
are  coarse,  those  of  the  C.  I.  are  fine.  If  one  of  these 
trans-sections  be  treated  with  alcohol  and  then  with  carmine 
the  portion  belonging  to  the  C.  I.  is  strongly  tinged,  while 
the  optic  fibres  remain  white.  The  same  reaction  has  been 
obtained  by  Mayser  in  the  T.  O.  of  cyprinoid  fishes.  In 
dogs,  cats,  monkeys,  and  man  no  such  chemical  distinction 
exists.  If  the  sections  of  rabbits'  T.  O.  are  placed  unstained 
(only  colored  by  potassium  bichromate)  in  glycerine,  the 
fibres  of  the  C.  I.  appear  as  forming  a  clearer  mass  in  the 
dark  field  of  the  optic  fibres. 

In  his  fourth  optic  contribution,'  von  Gudden  describes 
the  appearance  of  the  optic  apparatus  in  a  human  case  of 
long-standing  one-sided  blindness.  Those  parts  in  the 
chiasma  and  tractus  optici  which  correspond  to  the  C.  I.  he 
found  unchanged,  but  not  distinctly  limited,  and  made  up 
of  fibres  having  the  same  diameter  as  the  optic  fibres.  The 
C.  I.  in  these  trans-sections  was  dorsal  of  the  optic  fibres. 
In  the  chiasma  of  animals  it  occupies  the  caudal,  or  the 
caudal-ventral,  aspect. 

In   his   "  Experimentaluntersuchungen,"  he   states,   that 

^  Archiv  f.  Ophthal.,  Bd.  xxv,  Heft  4,  pp.  237-246,   1879. 


lO 


GUDDEN'S  ATROPHY  METHOD. 


the  study  of  numerous  trans-sections  of  the  brain  has  shown 
that  the  commissura  inferior  extends  into  the  thalami  optici, 
connects  them,  and  is  probably  in  no  wise  associated  with 
the  optic  apparatus.  After  destruction  of  the  lobus  opticus 
and  the  corpus  geniculatum  laterale,  the  commissura  infe- 
rior remains  unchanged. 

In  connection  with  these  important  studies  upon  the 
commissural  systems  of  the  brain  (corpus  callosum,  com- 
missura anterior,  and  commissura  inferior)  von  Gudden  has 
formulated  the  following  law  of  atrophy  (of  nutrition) : 

That  a  true  commissure,  separated  from  one  of  its  attach- 
ments, must  undergo  bilateral  atrophy. 


UA^. 


III. — Distribution  of  fibres  in  the  optic  apparatus. 

As  stated  in  the  four  articles  in  Grcefe's  Archiv,  von  Gud- 
den has  reached  the  following  conclusions  : 

1.  That  in  birds  there  is  complete  decussation  of  fibres  in 
the  optic  chiasma. 

ExpT. — Removal  of  one  eyeball  in  a  pigeon  immediately  after 
birth.  Autopsy  in  eight  weeks  showed  atrophy  of  optic  nerve 
of  same  side,  extending  across  the  woven  chiasm  to  the  opposite 
optic  lobe,  which  is  much  reduced  in  size. 

2.  In  the  higher  mammalia  the  decussation  is  variable, 
but  is  always  a  semi-decussation. 

ExPT. — In  a  rabbit,*  the  right  eyeball  was  enucleated.  Results  : 
{a)  atrophy  of  right  optic  nerve  ;  {b)  chiasma  unchanged  ;  {c) 
opposite  (left)  tractus  opticus  jwuHlb,  as  are  also  {d)  the  lobus 
opticus,  and  {e)  the  corpus  geniculatum  laterale  ;  {/)  complete 
atrophy  of  opposite  left  tractus  peduncularis.  Negative  results  : 
post-optic  lobes  (corpus  quadrigeminum  inf.)  and  commissura 
inferior  normal. 

This  experiment  seemed  to  show  that  there  was  complete 

'  It  was  always  in  newly-born  animals  that  the  various  operations  were  done. 


E.    C.    SEGUIN.  II 

decussation  in  the  rabbit,  and  so  Gudden  held  for  some 
years,  but  different  experiments,  published  in  1879,'  demon- 
strated beyond  question  the  existence  of  a  direct  fasciculus 
in  the  optic  nerve  of  this  animal. 

ExPT. — By  means  of  a  sharp  spoon,  the  optic  lobe,  corpus 
geniculatum  externum,  subjacent  part  of  caudex,  and  correspond- 
ing optic  tract  are  removed.  Autopsy  at  age  of  six  months. 
Results  :  [a)  total  atrophy  of  injured  tractus  opticus  ;  {!))  oppo- 
site optic  nerve  atrophies  in  greater  part,  but  still  showing  a  small 
normal  white  fasciculus. 

ExPT. — The  brain  was  lifted  up,  and  one  half  of  chiasm 
cut  out  with  a  sharp  spoon.  Results  :  complete  atrophy  of  the 
optic  fibres,  except  a  small  (lateral)  bundle  in  opposite  optic 
nerve — its  direct  fasciculus — (in  this  experiment  the  comraissura 
inferior  undergoes  atrophy,  as  does  also  Meynert's  commissure 
dorsal  of  tractus). 

As  complementary  to  these  results  may  be  added  the  fact  that 
one  of  Gudden's  assistants.  Dr.  Bumm,*  carefully  examined  the 
retina  of  the  eye  receiving  only  the  direct  fasciculus,  and  found 
the  nerve-fibre  layer  atrophied,  except  in  the  lateral  (temporal) 
segment  of  the  organ.  The  retina  was  hardened  in  osmic  acid, 
and  the  whole  of  it  cut  and  prepared. 

Consequently,  it  must  be  held  as  demonstrated  that  in 
rabbits  there  is  semi-decussation,  but  to  a  slight  degree  only, 
as  the  crossed  fasciculus  is  enormously  larger  than  the 
direct  ;  and  that  this  small  direct  fasciculus  supplies  the 
temporal  part  of  the  retina  in  'ologifti  r/V^ 

ExPT. — Right  eyeball  enucleated.  Results  :  {a)  complete 
atrophy  of  right  optic  nerve  ;  \b)  both  optic  tracts  reduced  in 
size,    the    left    smaller  ;  {c)    both  optic  lobes  smaller  ;  {d)    both      /  / 

corpora     geniculata    laterala    smaller  ;     {e)     caudal     ^^^^     of      /^ 
thalami  smaller  ;  (/)  tractus  peduncularis   smaller.     The  commis-^ 
sura  inferior  was  preserved. 

ExpT. — "  Optic   centres  "  (lobus  opticus  and  corpus   genicu- 

^  Arch.  f.  Ophthal.,  Bd.  xxv,  i,  pp.  1-56,  1879. 

"  Bumm  :  Ueber  die  Vertheilung  des  Sehnerven  in  der  Netzhaut  des  Kanin- 
chens.      WestphaVs  Arckiv,  Bd.  xi,  p.  264,  1881. 


12 


GUDDEN'S  ATROPHY  METHOD. 


/ 


latum  laterale)  removed  on  right  side.  Results  :  («)  tractus  op- 
ticus of  same  side  atrophied  ;  (^)  both  optic  nerves  reduced  in 
size,  opposite  (left)  smaller  ;    {/)  commissura  inferior  preserved. 

In  dogs,  consequently,  there  is  also  semi-decussation,  to  a 
greater  extent  than  in  rabbits,  but  still  the  direct  fasciculus 
is  smaller  than  the  crossed. 

The  course  of  the  direct  fasciculus  in  the  dog  (as  seen 
in  horizontal  sections  of  chiasm  from  above  experiment), 
lies  in  the  dorsal  border  of  right  tractus  opticus;'  reaching 
the  chiasm  it  passes  over  the  crossed  fasciculus  from  the 
other  tractus,  and  then  farom  the  medial  border  of  the  optic 
nerve  on  same  side  (right).  In  rabbits  this  fasciculus  lies  in 
the  lateral  border  of  optic  nerve. 

Numerous  experiments  of  these  kinds  are  recorded  in  the 
various  papers,  and  elaborate  measurements  given  of  the 
areas  of  the  affected  optic  nerves  and  tracts. 

Gudden  formulates  the  law  of  atrophy  in  the.  optic  ap- 
paratus as  follows  : 

1.  The  optic  nerves  and  tracts  degenerate  (undergo 
atrophy)  when  the  retina  is  destroyed  (removed). 

2.  The  "  optic  centres"  (lobus  opticus  and  corpus  geni- 
culatum  laterale)  also  undergo  atrophy  in  such  a  case. 

3.  When  the  centres  are  removed,  the  degeneration  does 
not  involve  the  retina. 

In  man,  reasoning  by  analogy  from  the  higher  mammals 
experimented  on  it,  would  seem  that  semi-decussation  were 
a  logical  necessity,  yet  several  advocates  of  complete  decus- 
sation have  appeared.'  The|#  arguments  have,  however, 
been  very  weak,  and  Gudden  made  short  work  of  their  few 
experimental  claims.^  Cases  of  long-standing  monocular 
blindness  in  man,  fitted  for  the  direct  solution  of  the  prob- 
lem, are  not  infrequent,  but  few  of  them  have  been  properly 

'  Chiefly  Michel,  Arch.  f.  Ophikal.,  Bd.  xxiii,    Heft  2,  pp.  213-226,  1877. 
"^  Arch.  f.  Ophthal.,  Bd.  xxv,  Heft    I,  pp.  I-56,  1879. 


E.    C.    SEGUIN.  13 

studied.     Von  Gudden  has  had  the  opportunity  of  examin- 
ing four  such  cases. 

Case  i. — Man  eighty-five  years  old  ;  blind  in  one  eye  from 
early  youth  :  phthisis  bulbi.  The  atrophy  is  not  total,  many 
normal  nerve-fibres  being  found  in  affected  optic  nerve.  Both 
tractus  smaller  than  normal. 

Case  2. — Man  thirty  years  old  ;  complete  atrophy  of  left  optic 
nerve  (not  one  fibre  found  in  a  careful  microscopic  examination)  ; 
both  tractus  reduced  in  size,  one  on  opposite  side  smaller. 

Case  3. — Male,  dying  at  sixty,  with  left  hemiplegia.  Thirteen 
years  previously  had  had  an  attack  of  "  apoplexy."  Besides  the 
lesion  in  one  internal  capsule  explaining  the  hemiparesis,  there 
was  found  an  old  hemorrhage  which  had  destroyed  the  left  corpus 
geniculatum  laterale,  part  of  the  thalamus  opticus,  and  part  of  the 
tractus  opticus.  The  whole  tractus  was  atroyjhied  ;  the  oppo- 
site optic  nerve  smaller,  and  the  nerve  on  same  side  contained 
many  atrophied  fibres,  and  was  smaller  (on  section)  in  its  medial 
and  central  fasciculi.  (The  case  is  obscurely  reported,  and  there 
seems  to  be  an  error  in  the  designation  of  the  optic  nerves.) 

Case  4.' — Woman,  aged  seventy-three  years.  Glaucoma  and 
complete  loss  of  sight  in  right  eye  for  four  years.  The  right 
optic  nerve  was  completely  atrophied  ;  the  right  tractus  opticus 
seemed  normal  to  naked  eye  ;  the  left  tractus  was  smaller  and 
mostly  gray  ;  on  the  chiasma  itself,  and  upon  the  left  tractus, 
crossing  chiasm  from  the  frontal  medial  border  of  left  optic  nerve, 
was  a  projecting  white  band,  the  direct  fasciculus  from  left  eye. 
The  microscope  showed  the  left  tractus  all  gray  except  in  its 
dorsal  aspect,  where  some  normal  nerve-fibres  were  seen  ;  the 
right  tractus,  on  the  other  hand,  presented  (in  sections)  only 
a  small  area  of  atrophied  fibres  (the  direct  fasciculus  from  the 
right  eye,  and  the  commissura  inferior).  The  degeneration  and 
atrophy  extend  to  the  optic  centres,  /.  e.,  the  left  corpus  genicula- 
tum laterale  and  lobus  opticus. 

These  cases  certainly  favor  the  theory  of  semi-decussation. 

The  following  is  a  general  sun:imary  of  von  Gudden's  re- 
sults with  respect  to  the  optic  apparatus. 

I.  That  Johannes  Miiller's  law  (which  was  only  a  physio- 
logical   postulate),  that   in   animals  whose  visual   axes    are 

^  Arch.  f.  Ophthal.,  Bd.  xxv,  Heft  4,  pp.  237-246,  1879. 


14  GUD DEN'S  ATROPHY  METHOD. 

only  lateral  (monocular  vision)  there  is  total  decussation, 
and  that  in  animals  whose  visual  axes  are  more  or  less  di- 
rected forward  (more  or  less  perfect  binocular  vision)  there 
is  semi-decussation,  is  a  good  law,  supported  by  his  (Gud- 
den's)  experiments  and  other  facts. 

2.  That  there  is  no  anterior  commissural  (inter-retinal) 
fasciculus  in  the  optic  apparatus, 

3.  That  the  posterior  commissural  fasciculus  of  classic 
authors  is  his  commissura  inferior,  which  has  no  relation  to 
the  optic  system. 

4.  That  the  optic  system  in  mammals  consists  only  of 
two  bundles  or  fasciculi,  one  crossed  and  the  other  direct ; 
the  former  the  larger  in  rabbits,  dogs,  and  cats  (and  quite 
certainly  in  man). 

5.  That  there  is  an  accessory  optic  fasciculus,  whose  cen- 
tral and  peripheral  terminations  are  yet  unknown,  viz.,  the 
tractus  peduncularis  transversus. 

6.  That  each  optic  tract  is  composed  of  three  sorts  of 
fibres,  of  the  same  size  in  man,  of  different  sizes  and  differ- 
ent carmine  reaction  in  animals  ;  optic  fibres  (crossed  and 
direct),  fibres  of  the  commissura  inferior,  and  "  hemispheric 
fibres,"  whose  course  is  not  well  known.  These  last- 
named  fibres  are  in  the  most  lateral  part  of  the  tractus  and 
pass  into  the  crus  cerebri. 

These  results  were  confirmed  by  the  experiments  of 
von  Gudden's  pupil — Ganser — on  cats,  published  last  year.' 
This  able  observer  has  also  carried  the  inquiry  further,  as 
regards  the  cortical  and  retinal  distribution  of  optic  fibres, 
affording  a  remarkable  concurrence  between  von  Gudden's 
results  and  Munk's. 

Ganser  chose  cats,  for  several  reasons.  They  are  vigorous 
under    operative    interference ;  they   are    more    intelligent 

^  Ueber  die  periphere  und  centrale  Anordnung  der  Sehnervenfasern  und  iiber 
das  Corpus  bigeminum  anterius,    Westphal's  Archiv,  Bd.  xiii,  Heft  2,  1882. 


E.    C.    SEGUIN.  15'. 

than  rabbits,  so  that  one  can  test  their  visual  field  ;  they 
have,  to  a  remarkable  degree,  binocular  vision,  and  thus  re- 
semble man  ;  their  retina  has  a  very  high  and  clearly  de- 
fined structure,  thus  affording  excellent  opportunity  for 
ophthalmoscopic  and  microscopic  study. 

He  relates  three  crucial  experiments  as  follows  : 

ExPT.  I. — For  the  determination  of  the  direct  fasciculus.  On  the 
third  day  after  birth,  the  left  eyeball  of  a  kitten  was  enucleated. 
A  fine  forceps  was  introduced  through  the  foramen  opticorum,  and 
the  tractus  opticus  of  the  same  side  torn  or  cut  (at  the  same  time 
unintentionally  a  slight  wound  was  made  in  the  infundibulum  and 
left  internal  capsule).  Cat  recovered  quickly  and  grew  normally  ; 
was,  however,  lazy  or  stupid,  more  so  than  a  brother  kitten  who- 
had  lost  one  hemisphere.  Vision  seemed  good  till  tested,  when 
it  was  found  it  had  hemianopsia,  /.  <?.,  was  using  only  the  temporal 
half  of  its  remaining  retina.  Autopsy  at  nine  months.  The  only 
part  of  optic  apparatus  left  was  a  white  nerve  extend- 
ing from  right  eyeball  to  the  optic  centres  of  same  side  ;  no 
chiasm.  Right  optic  lobe  and  corpus  geniculatum  laterale 
larger.  The  right  tractus  peduncularis  transversus  was  smaller 
than  normal,  the  left  almost  invisible  ;  commissura  inferior  ab- 
sent. Sections  of  the  hardened  retina  showed  normal  nerve- 
fibres  (amyelinic  in  cat),  only  in  its  temporal  two  thirds  ;  on 
nasal  side  fibres  and  ganglionic  bodies  atrophied. 

Conclusion  :  there  is  a  true  fasciculus  lateralis  (or  direct 
fasciculus)  in  the  optic  system  of  the  cat,  and  it  supplies  the- 
temporal  part  of  the  retina. 

ExPT.  2. — To  determine  the  relation  between  the  occipital  cor- 
tex and  the  optic  apparatus. 

In  a  kitten  of  same  litter  a  portion  of  the  left  occipital  lobe 
was  removed  without  wounding  the  cornu  ammonis  or  the  basal 
ganglia.  The  injury  was  smaller  but  similar  in  location  to  that 
done  to  a  dog's  brain  by  von  Gudden.'  This  cat  had  no  symp- 
toms, but  special  tests  (by  means  of  a  white  ball  swung  around 
the  cat  in  direct  and  inverse  directions)  revealed  right  homony- 
mous     hemianopsia.      Ophthalmoscopic      examination     showed 

^  Archiv  f.  Ophthal.,  Bd.  xxi,   Heft  3,  pp.   199-205,   1875. 


l6  GUDDEN'S  ATROPHY  METHOD. 

morbid  changes  in  the  temporal  two  fifths  of  the  left  retina,  and  in 
the  right  eye  more  than  the  medial  (nasal)  half  was  atrophied. 
Autopsy  at  nine  months.  Left  hemisphere  shows  scar  opening 
freely  into  lateral  ventricle  (no  inflammatory  action).  Left  tractus 
opticus  smaller  than  right,  revealing  more  of  Meynert's  commis- 
sure on  the  crus.  The  optic  nerves  seemed  little,  if  at  all,  changed 
to  the  naked  eye,  but  on  measuring  the  area  of  sections  under 
the  microscope,  the  right  nerve-sections  were  found  smaller. 

Microscopic  examination  of  the  hardened  retinae  showed  no 
local  elemental  atrophy,  but  there  was  distinct  thinning  of  the 
retina  in  both  left  halves  (left  temporal  and  right  nasal  halves), 
especially  distinct  in  the  papillae. 

ExPT.  3. — For  the  same  purpose.  In  a  third  kitten  the  left 
hemisphere  of  the  cerebrum  was  nearly  all  removed,  the  corpus 
callosum  and  fornix  being  carefully  cut  in  the  medial  line.  The 
animal  grew  well  and  was  not  at  all  paralyzed.  The  only  move- 
ment which  he  learned  late  was  springing  up  on  a  chair,  etc. 
Was  dull  and  had  a  bad  memory.  Tactile  sensibility  and  reflex 
movements  seemed  normal,  but  pricking  was  but  little  felt  over 
whole  body.  As  in  the  former  cat,  there  was  right  homonymous 
hemianopsia.  Ophthalmoscope  showed  tlie  temporal  part  of 
retina  atrophied  in  left  eye,  while  in  the  right  the  morbid  changes 
extended  over  two  thirds  of  the  retina  (more  than  nasal  half). 
Autopsy  at  six  months.  Large  serous  sac  in  left  brain  ;  olfactory 
bulb  and  lobe,  base  of  temporal  lobe,  and  basal  ganglia  unin- 
jured ;  left  thalamus  smaller  ;  internal  capsule  atrophied  ;  left 
half  of  pons,  and  left  crus  cerebri  smaller  ;  left  anterior  pyramid 
absent  ;  left  optic  centres  (optic  lobe  and  corpus  genie,  laterale) 
are  smaller.  Both  tractus  optici  smaller  than  those  of  normal 
kittens  of  same  age  ;  left  more  reduced.  Under  microscope  the 
section-areas  of  both  optic  nerves  diminished,  right  more.  Sec- 
tions of  hardened  retinae  showed,  as  in  former  case,  a  thinning  of 
retinal  layers  in  both  left  halves — left  temporal  and  right  nasal 
segments. 

Conclusions :  In  cats  the  crossed  fasciculus  is  larger 
than  the  direct.  In  cats  there  is  an  anatomical  connection 
between  the  hemispheres  (visual  area  in  occipital  lobe)  and 
the  optic  centres,  extending  thence  to  the  retinae. 

Gudden's    old  experiment,'  shov^'ing   that  in    rabbits   re- 

'  Experimentaluntersuchungen.  etc.    Westphars  Archiv,  Bd.  ii,  p.  693,  1870. 


E.    C.    SEGUIN.  17 

moval  of  one  hemisphere  has  no  influence  on  optic  nerves, 
was  repeated  with  the  same  results  in  six  young  rabbits. 

It  would  thus  appear  that  in  lower  mammals  (those  with 
insignificant  binocular  vision)  the  optic-nerve  fibres  are  chiefly 
collected  in  the  optic  centres  (optic  lobe  and  corpus  genicu- 
latum  laterale),  while  in  higher  mammals,  dogs,  cats,  mon- 
keys, as  in  man,  there  is  a  large,  better  differentiated  cor- 
tical connection. 

The  new  and  most  interesting  question  of  the  anatomical 
relation  existing  between  the  layers  of  the  optic  lobes  and 
the  peripheral  optic  apparatus  on  the  one  hand,  and  the 
visual  area  of  the  cortex  cerebri  on  the  other  hand,  was 
studied  in  the  rat  as  follows  : 

ExPT.  A. — White  rat  three  days  old.  Right  eye  enucle- 
ated. Autopsy  at  nine  months.  Right  optic  nerve  atrophied  ; 
left  tractus  much  smaller  than  right  ;  left  optic  lobe  and  corpus 
geniculatum  laterale  flatter  and  smaller. 

ExpT.  B. — White  rat  three  days  old  ;  removal  of  convex  part  of 
right  cerebral  hemisphere  (part  of  cornu  ammonis  also  removed). 
Autopsy  in  nine  months.  Both  optic  nerves  alike  ;  right  thalamus, 
optic  lobe,  and  corpus  geniculatum  a  little  smaller.  Right  inter- 
nal capsule  atrophied,  crus  cerebri  smaller,  anterior  pyramid 
absent. 

The  brains  were  subdivided  into  segments  and  hardened  in  a 
two-per-cent  solution  of  osmic  acid  (24  hours),  and  later  in  alco- 
hol. The  optic  lobes  were  cut  into  fine  trans-sections,  which 
were  carefully  examined.' 

In  rat  A  there  was  a  reduction  of  the  left  superficial  gray,  and 
nearly  total  atrophy  of  the  superficial  white  {fibre  visiva  of  Tartu- 
feri^);  intermediate  white  normal  on  both  sides.  [Effects — one- 
sided in  rat  because  of  insignificance  of  direct  fasciculus.] 

In  rat  B,  on  the  right  side,  the  intermediate  white  was  reduced, 
and  there  was  also  partial  atrophy  of  the  right  side  of  the  tubular 
gray  (from  what  cause  ?). 

'  In  the  normal  optic  lobe  Ganser  distinguishes  the  following  layers  :  i.  zonal 
fibres  (present  only  in  higher  mammals)  ;  2.  superficial  gray  ;  3.  superficial 
white ;  4.  intermediate  gray  ;  5.  intermediate  white  ;  6.  deep-seated  white  ; 
and  7.  the  tubular  gray. — Ganser:  Vergleichend-anatomische  Studien  iiber 
das  Gehirn  der  Maulwurfs.     Morphol.  Jahrbuch,  Bd.  vii,  p.  711. 

'^  Fibre  di  origine  del  (ratio  ottico   in  the  strata   bianco-chiereo  superficiale  of 


1 8  GUDDEN'S  ATROPHY  METHOD. 

Conclusions  :  In  rats  the  peripheral  optic  apparatus  is 
more  intimately  connected  with  the  superficial  gray  and 
white  layers  of  the  optic  lobes,  while  the  visual  area  of  the 
cerebrum  is  mostly  in  relation  with  the  intermediate  white 
layer. 

It  may  not  be  wholly  superfluous  to  add  that  an  impor- 
tant negative  conclusion  from  the  work  of  von  Gudden  and 
his  pupils  is,  that  neither  the  post-optic  lobes  (corpora 
quadrigemina  inferior)  nor  the  corpora  geniculata  medialis 
are  connected  with  the  optic  apparatus  ;  a  view  which  is 
borne  out  by  morphological  conditions,  etc. 

IV. —  Tr actus  peduncularis  transversiis. 

When  von  Gudden  published  his  first  account  '  of  this 
interesting  fasciculus  he  was  unaware  that  it  had  long  been 
known  ;  but  he  himself  rectified  his  error  by  giving  a  biblio- 
graphical account  of  it  along  with  his  later  experiments.'' 
The  bundle  was  unknown  to  most  of  the  older  anatomists, 
but  Gall  and  Spurzheim^  described  and  figured  it  in  several 
plates  as  early  as  1810.  Von  Gudden  knew  it  (in  con- 
nection with  his  first  optic  experiments)  as  early  as  1849. 
In  Leuret  and  Gratiolet's  atlas"  it  is  drawn  by  the  artist 
but  not  referred  to  by  the  author  (Gratiolet).  An  Italian 
investigator  appears  to  have  described  it  in  1861,  under  the 
name  oi  fascio  transversa.  ^ 

Tartuferi.     (Sull'   anatomia   minuta   dell'   eminenze   bigemine   anteriori   delle 
scimmie.     Rivista  Sperimentale  di  Freniatria,  v,  F.  iii,  1879. 

'  Ueber  einen  bisher  nichbeschreibenen  N erven faserung  im  Gehirn  der  Sau- 
gethiere  und  das  Menschen.      Westphal's  Archiv,  Bd.  ii,  p.  364, — 1870. 

^  Ueber  den  tractus  peduncularis  transversus.  WestphaFs  Archiv,  Bd,  xi, 
Heft  2,  1880. 

^  "  Atlas  d'anatomie  at  de  physiologic  du  systeme  nerveux  en  general  et  du 
cerveau  en  particulier."     Paris,  1810. 

*  "  Anatomic  comparee  du  systeme  nerveux."     Paris,  1857. 

^  A  proposal  has  recently  been  made  by  a  distinguished  American  zoologist, 
Wilder,  "  Anatomical  Technology,"  New  York  (1882),  to  change  this  name  to 
cimbia.  This  term  has  no  anatomical  sense  whatever  its  architectural  value 
may  be.     Von   Gudden's  name,  on  the  contrary,   if  long,  is  descriptive  and 


E.    C.    SEGUIN. 


As  its  name  correctly  implies  the  tractus  ped.  trans, 
traverses  the  crus  cerebri  (peduncul»»#).  It  apparently 
arises  from  just  within  the  medial  border  of  the  crus,  / 
passes  over  it  in  a  line  about  half-way  between  the  caudal 
edge  of  the  tractus  opticus  (and  Meynert's  commissure) 
and  the  frontal  border  of  the  pons,  extending  latera\  and 
dorsa%to  the  frontal  edge  of  the  lobus  opticus  where  it 
disappears.  The  tractus  ped.  tr.  is  thus  distinctly  traceable 
only  in  the  lower  mammalia  ;  in  man  it  is  but  slightly  visible 
in  a  part  of  its  course.' 

Von  Gudden  has  endeavored,  but  thus  far  in  vain,  to  de- 
termine the  true  origin  and  destination  of  this  fasciculus. 
As  regards  its  function  he  long  ago  learned  something  from 
his  various  extirpation  experiments  on  the  optic  apparatus. 
The  facts  have  already  been  incidentally  stated,  but  a  more 
direct  quotation  is  permissible. 

ExPT  — Extirpation  of  both  eyes  in  rabbit.  Results  :  atrophy 
of  optic  nerves,  of  optic  part  of  chiasm  and  tractus  optici,  of 
primary  optic  centres,  and  of  both  tractus  pedunc.  tr. 

ExpT. — Extirpation  of  one  eyeball  in  rabbit.  Results  :  atrophy 
of  optic  nerve,  of  opposite  optic  tract  (very  slight  of  tract  of  same 
side),  of  primary  optic  centres  of  opposite  side,  and  of  tractus 
pedunc.  tr.  of  opposite  side. 

ExPT. — In  the  dog  after  enucleation  of  one  eyeball  there  are  : 
atrophy  of  optic  nerve,  of  both  optic  tracts,  and  both  sets  of 
primary  optic  centres,  and  of  both  tractus  pedunc.  tr.  In  all  the 
parts  caudad  of  chiasm  the  atrophy  is  more  marked  on  the  side 
opposite  the  enucleation. 

ExpT. — Excision  of  part  of  occipital  lobe  in  a  dog,  and  re- 
moval of  one  optic  lobe  in  a  rabbit,  were  followed,  among 
other  results,  by  reduction  in  size  of  the  corresponding  tractus 
pedunc.  ir. 

Conclusions:  The  tractus  peduncularis  transversus  has  a 

equivalent  to  a  definition — consequently  it  is  good  and  should  be  retained. 
From  the  context  in  Wilder,  op.  cit.,  §  1203,  p.  475,  it  seems  that  he  does  not 
know  Gudden's  now  old  discovery  of  the  optic  nature  of  this  fasciculus. 

'  Cf.  Schwalbe  :   "  Lehrbuch  der  Neurologic,"  p.  459.     Erlangen,  1S81. 


20  GUD DEN'S  ATROPHY  METHOD. 

functional  and  anatomical  connection  with  the  optic  appar- 
atus— more  with  its  peripheral  part,  to  which  it  stands  in 
the  same  relation  as  the  crossed  fasciculus  of  the  tractus 
opticus.  Its  connection  with  the  primary  optic  centres  is 
direct,  but  less  intimate  ;  its  connection  with  the  visual 
area  of  the  cerebral  cortex  is  still  less  marked,  but  also 
direct. 


GUDDEN'S    ATROPHY    METHOD:    AND   A   SUM- 
MARY OF  ITS  RESULTS. 
{Second  PaperJ^) 

By  E.  C.  SEGUIN,  M.D. 
( With  two  wood-cuts.) 

DURING  the  month  of  October  of  this  year  I  went 
to  Munich  specially  to  see  Professor  von  Gudden's 
preparations  illustrating  the  various  propositions  advanced 
in  this  analysis,  and  he  very  kindly  showed  them  to  me 
himself  with  the  greatest  patience  and  system.  I  must  also 
thank  Dr.  Ganser  for  his  courteous  assistance  in  the  labora- 
tory, more  especially  with  respect  to  details  as  to  various 
points  of  technique. 

Before  proceeding  to  continue  the  enumeration  of  Gud- 
den's and  Ganser's  discoveries,  it  is  necessary  to  insert  cor- 
rections and  additions  relative  to  two  topics  treated  of  in 
the  first  paper. 

First,'  as  to  the  pars  olfactoria  of  the  commissura  anterior. 
Professor  von  Gudden  has  recently  been  led  to  return  to  his 
former  view  (against  Ganser),  that  this  commissure  does  not 
unite  the  bulbi  olfactorii,  but  the  lobi  o.  To  understand  the 
experimental  results,  one  must  have  a  clear  idea  of  Gud- 
den's view  of  the  anatomy  of  the  rabbit's  olfactory  bulb. 
He  considers  the  true  bulb  structure  to  sit  like  a  cap  over 
the  projected   extremity  of  the  lobus  olfactorius  ;  in  other 

*  Fide  Archives  for  October,  p.  126.  [This  paper  should  have  appeared  as 
editorial  matter,  but  was  placed  among  original  papers  because  the  editorial 
space  had  been  engaged. — Ed.] 

'  Unpublished. 

Reprinted  from  the  Archives  of  Medicine,  Vol.  x.  No.  3,  December,  1883. 


2  E.    C.    SEGUIN. 

words,  a  portion  of  cerebral  cortex  is  inclosed  within  the  bulb 
proper.  Consequently  it  is  impossible  to  remove  the  bulbus 
olf.  without  also  injuring  or  removing  a  portion  of  cerebral 
cortex  and  white  substance. 

Expt/ — The  lobus  olfactorius  is  simply  separated  by  incision 
from  its  connections  with  the  brain.  The  skull  is  not  opened, 
and  no  nervous  substance  removed.  Autopsy  shows  that  the 
separated  bulbus,  though  smaller,  has  retained  its  vitality,  and  the 
olfactory  nerves  are  normal.  Trans-sections  and  horizontal  sec- 
tions give  the  following  results  : 

In  the  bulbus  there  is  no  positive  atrophy  of  its  essential  ele- 
ments. In  the  olfactory  lobe  of  the  cerebrum  (inferior  part  of 
frontal  lobe)  there  is  distinct  though  slight  atrophy,  in  size  and 
number,  of  ganglion  cells  in  the  cortex.  In  the  centre  of  the 
bulbus  (inclosed  cerebral  substance)  the  white  substance  is  much 
atrophied.  The  tractus  olfactorius  shows  much  atrophy  of  its 
white  substance,  more  especially  the  lateral  fibres. 

Contrary  to  Ganser,  the  pars  olfactoria  of  the  C.  a.  is  to  a  great 
extent  preserved.  Some  fibres  are  atrophied  (absent),  viz.:  those 
which  in  the  normal  state  extended  into  the  intra-bulbar  projec- 
tion of  the  olfactory  lobe,  which  was  cut  off  by  the  incision. 

Consequently  von  Gudden  holds  that  the  pars  olfactoria 
of  the  commissura  anterior  connects  two  lobi  olfactorii,  a 
view  which  is  just  as  much  opposed  to  Meynert's  hypoth- 
esis as  the  former  was. 

Second,  an  addition  to  the  anatomy  of  the  optic  appara- 
tus. Last  year"  von  Gudden  presented  to  the  Science 
Congress  at  Eisenach  a  r^sum^  of  more  recent  experiments 
upon  the  various  constituents  of  the  optic  apparatus.  He 
repeated  his  demonstrations  that  the  commissura  inferior 
cerebri  and  the  hemispheric  fasciculus  of  the  tractus  opticus 
{vide  Archives  of  Medicine,  October,  p.  139)  are  not  di- 
rectly connected,  physiologically,  with,  the  visual  apparatus, 

'To  save  repetition  it  is  to  be  understood,  unless  specially  otlierwise  stated, 
that  the  experiments  cited  in  this  paper  are  made  upon  newly-born  rabbits, 
which  are  allowed  to  live  many  months  before  autopsy. 

'  Ueber  die  verschiedenen  Nervenfasernsysteme  in  der  Retina  und  im  Nervus 
opticus. —  Tageblatt  der  55  Versatmnlutig  der  Deulschen  A'aturforscher  und 
Aerzte,  Eisenach,  1882. 


GUD DEN'S  ATROPHY  METHOD.  3 

He  laid  the  results  of  new  experiments  before  the  Asso- 
ciation with  reference  to  : 

1.  The  relations  of  the  hemispheres  to  vision.  If  one 
hemisphere,  even  inclusive  of  its  corpus  striatum,  be  removed 
from  a  newly-born  rabbit,  it  is  impossible,  after  the  animal 
has  become  adult,  to  detect  any  impairment  of  sight  ;  and 
both  the  pupils  react  normally.  Gudden  does  not  generalize 
from  this  fact ;  he  simply  advances  it  as  true  in  rabbits.  He 
calls  attention  to  a  possible  explanation  of  the  conflict  be- 
tween this  result  and  Munk's  conclusions,  by  the  fact  that 
Munk  always  operated  on  adult  animals  (or,  at  least,  not 
on  the  newly-born)  whose  cerebrum  has  acquired  certain 
functional  attributes  absent  at  an  early  period  of  life. 

2.  Centre  of  pupillary  movements.  He  condemns  as 
erroneous  his  former  statement,  that  after  removal  of  one 
lobus  opticus  the  opposite^was  abnormal. 

{a)  If  one  successfully  removes  the  superficial  layers  of/ 
one  lobus  opticus  with  a  sharp  spoon,  it  is  observed  that  the 
animal  is  absolutely  blind  in  the  eye  opposite  the  lesion, 
but  the  pupils  are  both  normal  in  appearance  and  move- 
ments. Post-mortem  examination  shows  that  the  optic 
nerve  opposite  the  lesion  is  reduced  in  size,  but  is  white 
and  contains  normal  fibres.  The  retina  shows  a  general 
diffuse  reduction  in  the  number  of  its  nerve  fibres.  The 
tractus  ped.  transversus  on  the  operated  side  is  normal.  On 
careful  examination  one  sees  a  little  latero-frontad  of  the 
injured  lobus  opticus  a  small  eminence,  more  prominent 
than  on  the  opposite  normal  side.  The  eminence  is  ren- 
dered more  distinct  by  partial  atrophy  of  fibres  of  the 
tractus  opticus. 

{U)  If,  in  a  newly-born  rabbit,  we  remove  one  lobus  opti- 
cus, together  with  the  above-described  eminence,  the  adult 
animal  shows  blindness  of  the  opposite  eye  with  wide  dila- 
tation of  its  pupil — a  dilatation  which  is  only  slightly  af- 


4  E.    C.    SEGUIN. 

fected  by  the  strongest  daylight.  The  optic  nerve  and 
retina  are  as  described  supra,  but  the  tractus  peduncularis 
trans,  on  the  operated  side  is  completely  atrophied. 

Thus  two  "centres"  are  demonstrated  :  one  in  the  lobus 
opticus,  for  vision  ;  the  other  a  little  frontad  of  it,  for  reflex 
pupillary  movements. 

3.  The  corpus  geniculatum  laterale  is  a  third  "  centre," 
probably  a  trophic  centre  for  the  optic  tract  and  nerve, 
since  after  its  removal  these  parts  undergo  atrophy  just  as 
after  enucleation  of  one  eyeball  [except  that  the  direct 
(lateral)  optic  fasciculus  remains  normal  in  the  former  case]. 
The  various  experiments  bearing  upon  this  question  are 
not  yet  complete. 

4.  If  portions  of  one  lobus  opticus  be  removed,  there 
are  found  various  segments  of  localized  retinal  atrophy  (in 
contradistinction  to  the  diffuse  atrophy  noticed  after  re- 
moval of  the  whole  lobus  opticus).  Experiments  upon  this 
further  differentiation  of  nerve  fibres  are  in  progress. 

5.'  Within  a  year  Gudden  and  Ganser  have  been  success- 
ful in  dividing  the  optic  chiasm  longitudinally  by  passing 
a  long  narrow-bladed  knife  through  the  unopened  skull  and 
brain  at  the  vertex. 

Results  :  Complete  atrophy  of  crossed  fasciculi  of  optic 
chiasm,  with  preservation  of  the  lateral  fasciculi^mmmissura     /^ 
inferior  atrophied  bilaterally. 

f  pass  on  now  to  studies  in  other  regions  of  the  nervous 
centres,  continuing  the  enumeration  begun  in  the  former 
paper. 

V. — Demonstration  of  the  pyramidal  tract? 
In  1871,  soon  after  the  publication  of  Hitzig's  first  ex- 
periments on  the  cerebral  cortex,  von  Gudden  removed  the 

'  Unpublished. 

"^  Ueber  Dementia  Paralytica. — Correspondenzblatt  f.  Schweizer  Aerzie,  Bd. 
ii,  p.  79,  1872. 


GUDDEN'S  ATROPHY  METHOD.  5 

frontal  portion  of  one  hemisphere  (including  the  "  motor 
centres ")  in  newly-born  rabbits.  Preparations  from  the 
adult  brain  showed  atrophy  of  the  corresponding  crus 
cerebi  and  anterior  pyramid.  The  date  of  this  experiment 
is  noteworthy  ;  it  was  certainly  anterior  to  Flechsig's  pub- 
lications/ and  is  the  first  demonstration  of  the  continuity 
of  the  motor  or  pyramidal  tract  from  the  cerebral  cortex 
caudad.  The  experiment  has  since  been  repeated  on  the 
dog  with  even  more  striking  results.  Specimens  from  the 
dog  I  was  able  to  examine.  They  showed,  caudad  of  the 
atrophied  cerebral  area,  a  complete  absence  of  the  medial 
division  of  the  crus  cerebri,  of  the  pyramidal  fasciculi  in  the 
pons,  and  of  the  pyramid  strictly  speaking.  Below  the 
decussation  the  atrophy  can  be  traced  in  the  posterolateral 
column  of  the  opposite  side.  The  anterior  columns  are 
unchanged.  The  lemniscus  {scJileife)  is  also  much  atrophied 
on  the  operated  side  (compare  statements  in  paragraph  on 
fasciculus  ad  tegmentum,  infra). 

VI. — Coimections  of  the  cerebellum.  ^ 

ExPT. — In  a  newly-born  rabbit  one  half  of  the  cerebellum  was 
removed.  At  the  autopsy  of  the  adult  animal  it  was  found  that  a 
very  small  part  of  the  lateral  portion  of  the  hemisphere  remained 
attached  to  the  medulla.'  A  full  series  of  trans-sections  was  made 
and  studied.     Results  : 

1.  In  the  upper  cervical  region  complete  atrophy  (absence)  of 
the  fasciculus  ad  cerebellum  *  {Kleinhirnseitensirangbahn  of 
Flechsig)  on  the  same  side  as  the  lesion. 

2.  In  the  caudal  part  of  the  medulla,  we  find  likewise  on  the 
same  side  as  the  injury  :  {a)  atrophy  of  a  group  of  cells  lying 
ventral   in  the  medulla  ("nucleus  of  anterior  columns"),  and  of 

'Yet  Flechsig,  in  his  most  recent  publication  ("Plan  des  Menschlichen 
Gehirns,"  p.  vii,  note  ;   Leipzig,  1883),  still  claims  the  demonstration  as  his. 

*  Ueber  die  Verbindungsbahnen  des  kleinen  Gehirns. —  Tageblatt  der  55  Ver- 
sarnmhing  der  Deuischen  Naturforscher  iind  Aerzte,  im  Eisenach,  1882. 

^  It  was  also  found  that  one  post-optic  lobe  was  much  injured,  and  that  the 
corresponding  crus  cerebri  had  been  touched  by  the  spoon. 

*  I  would  propose  this  term,  fasciculus  ad  cerebeUum,  for  the  ascending 
cerebellar  fasciculus.  It  is  in  harmony  with  the  names  of  adjacent  centripetal 
bundles,  viz.,  the  fasciculus  cuneatus  and  the  fasc.  gracilis. 


6  E.    C.    SEGUIN. 

(d)  a  second  cell-group  lateral  in  the  medulla  but  ventrad  of  the 
trigeminal  root,  the  so-called  "  nucleus  lateralis,"  from  its  sup- 
posed connections  with  the  lateral  columns.  In  this  region  the 
fibrse  arciformes  which  go  to  form  the  beginning  of  the  corpus 
restiforme  are  absent. 

d.  Sections  further  frontad  in  the  medulla  show  atrophy  of 
another  nucleus  on  the  same  side  as  the  injury,  one  situated  dorsad 
of  ascending  root  of  N.  v.  At  level  of  N.  vii  there  is  complete 
absence  of  the  corpus  restiforme. 

4.  In  the  various  sections  of  the  medulla  it  is  seen  that  the 
olive  of  the  side  opposite  the  lesion  is  almost  wholly  atrophied  ;  a 
small  part  of  it  is  still  seen  in  the  caudal  sections,  and  probably 
its  survival  is  due  to  the  bit  of  cerebellum  which  was  left  in  the 
operation. 

5.  Sections  in  the  region  of  N.  viii,  and  further  frontad,  show 
a  normal  state  of  this  nerve,  of  the  upper  olives,  trapezium,  and 
of  the  (falsely)  so-called  "  external  auditory  nucleus,"  or  Deiters' 
nucleus.  The  inner  division  of  the  processus  ad  medullam  is  about 
normal  ;  while,  as  already  stated,  its  outer  portion,  or  corpus 
restiforme,  is  totally  (?)  atrophied. 

6.  Sections  through  the  upper  part  of  the  pons  Varolii  show 
absence  of  processus  ad  pontem,  without  atrophy  of  trapezium  or 
of  upper  olives.  It  is  exceedingly  difficult  to  determine  the  con- 
nections of  the  atrophied  fibres,  but  many  of  them  were  certainly 
in  the  opposite  half  of  the  pons,  a  few  in  the  corresponding  half, 
and  others  were  true  commissural  fibres. 

7.  Sections  further  frontad  show  absence  of  the  processus  ad 
cerebrum  on  the  operated  side.  The  cells  of  the  descending  root 
of  N.  V  are  absent.  Further  on  the  nucleus  tegmenti  of  the  oppo- 
site side  is  almost  entirely  atrophied.  The  few  cells  remaining 
are  to  be  considered  as  evidence  that  another  fasciculus  probably 
arises  from  the  nucleus  tegmenti  and  proceeds  frontad.  That 
this  survival  of  a  few  cells  is  not  due  to  incomplete  decussation  of 
the  processus  ad  cerebrum  is  shown  by  the  absolutely  normal 
state  of  the  other  nucleus  :  were  there  a  semi-decussation,  both 
nuclei  would  exhibit  atrophy.  The  preserved  cell's  of  the  nucleus 
tegmenti  are  large,  and  are  situated  laterad  of  roots  of  N,  iii. 
Further  frontad  the  number  of  cells  in  both  nuclei  tegmenti 
become  equal. 

Consequently  it  may  be  stated  that : — 

I,     The  processus  ad  medullam  (or  corpus  restiforme)  has 


GUD DEN'S  ATROPHY   METHOD.  7 

four  origins,  viz.:  in  three  cell-groups  or  nuclei  on  the  same 
side  in  the  medulla  oblongata,  a  dorsal,  a  lateral,  and  a 
ventral  nucleus '  ;  it  is  also  derived  from  the  olive  of  the 
opposite  side. 

2.  The  processus  ad  pontem  arises  chiefly  from  cells  in  the 
opposite  half  of  the  pons.  It  does  not  give  fibres  to  the 
pyramidal  tract.  Prof.  Gudden  does  not  consider  his  re- 
searches on  this  point  concluded. 

3.  The  processus  ad  cerebrum  proceeds  frontad,  as  is 
well  known,  and  wholly  decussates  with  its  fellow,  and  has 
its  cell-connections  in  the  caudo-medial  part  of  the  opposite 
nucleus  tegmenti. 

VII. — Connections  of  the  processus  ad  cerebrum. 
In   1881,  my  friend,  Prof.  A.  Forel,  of  Zurich,  presented 
to  the  German  Science  Congress  at  Salzburg  the  results  of 
a  most  interesting  experiment  upon  this  organ." 

ExpT. — In  a  newly-born  rabbit  the  right  processus  ad  cere- 
brum, the  right  side  of  velum  medullare  anterius,  post-optic  lobe, 
and  (involuntarily)  a  small  bit  of  the  right  processus  ad  pontem 
were  removed. 

Results  :  Atrophy  of  remaining  (caudad  and  frontad  of  wound) 
fibres  of  processus  ad  cerebrum.  The  atrophy  is  easily  traced 
frontad  across  the  median  line  to  the  left  nucleus  tegmenti,  which 
is  largely  atrophied,  more  especially  in  its  caudal  part.  Sections 
frontad  of  nuclei  tegmenti  show  no  lesions.  The  ventral  decussa- 
tion of  the  tegmentum  {ventrale  Haubenkreiizung)  is  slightly  un- 
equal on  the  two  sides. 

But  it  is  in  the  sections  caudad  of  the  injury  that  the  most 
interesting  fact  is  found. 

The  right  half  of  the  vermis  superior  is  extremely  atrophic  ; 
some  fasciculi  going  to  the  nucleus  dentatus  are  visibly  atrophied. 
The  nuclei  (dentatus,  dectiformis,  embolus),  as  well  as  the  corpus 
restiforme,  are  perfectly  normal. 

'  This  last  was  known  to  Deiters  as  an  origin  for  fibres  for  the  corpus  resti- 
forme, and  Prof.  Gudden  has  called  it  Deiters'  nucleus  ;  but  as  this  term  has 
been  more  generally  applied  to  the  remarkable  group  of  large  cells  which  are  in 
seeming  relation  to  the  acoustic  nerve,  he  will  abandon  the  name. 

"^  Sitzungsberichte  der  54  Versammlung  Deutschen  Naturforscher  und 
Aerzte,  im  Salzburg,  1881.     In  Wiejier  med.  Zeittmg,  No.  46,  1881. 


8  E.   C.    SEGUIN. 

Other  lesions  noted  are  :  In  consequence  of  the  removal  of  the 
post-optic  lobe,  there  is  a  reduction  in  the  volume  of  the  right 
lateral  lemniscus  {Sch/eifensc/iicht)  as  far  caudad  as  N.  vii. 
Further  caudad  no  lesions.  There  is  slight  atrophy  of  the  so- 
called  crus  of  the  post-optic  lobe  as  far  frontad  as  the  corpus 
geniculatum  mediale,  which  seems  normal.  The  only  change  in 
the  lobi  optici  is  a  very  slight  reduction  of  the  deep  white  layer 
on  the  right  side.  The  r.  descending  root  of  N.  v  is  almost 
entirely  absent,  a  few  cells  remaining  at  the  level  of  the  exit  of  the 
nerve.  N.  viii  is  normal,  as  is  also  the  fountain-like  decussation 
{Fontaineartige  Kreutzung  of  Forel)  in  the  tegmentum,  which 
Meynert  and  Wernicke  would  associate  with  N.  v. 

The  important  conclusion  drawn  from  this  experiment  is 
that  the  processus  ad  cerebrum  arises  in  the  vermis  superior 
of  one  side,  and  terminates  (wholly?)  in  the  nucleus  teg- 
menti  of  the  opposite  side. 

VIII. — Central  connections  of  the  sciatic  nerve. 

This  subject  has  been  studied  by  means  of  Gudden's 
method  by  his  pupil  and  assistant,  Mayser.'  He  gives  a  de- 
tailed account  of  the  histology  and  architecture  of  the 
rabbit's  spinal  cords.  Then  he  takes  up  the  study  of  some 
cords  from  which  the  sciatic  nerve  had  been  separated  im- 
mediately after  birth,  two  by  extraction  of  roots,  and  one 
by  section  of  the  nerve. 

The  lesions  found  in  the  spinal  cord  are  similar  in  nature 
and  general  distribution,  but  more  extensive  and  distinct  in 
the  cases  of  extraction. 

Results  :  WJiite  substance.  The  only  marked  change  is  in 
the  posterior  columns  of  the  lumbar  enlargement,  which 
are  reduced  in  size  on  the  same  side  as  the  injury.  The 
fasciculus  cuneatus  is  alone  atrophied,  and  this  lesion 
gradually  diminishes  in  the  dorsal  region.  In  my  examina- 
tion of  the  specimens  I  observed  in  the  lumbar  region  com- 

'  P.  Mayser  :  Experimentaller  Beitrag  zur  Kenntniss  des  Ba^^s  des  Kanin- 
chen-Ruckenmarks.  Inaugural  Dissertation. —  iVestphaVs  Archiv  fiir  Psy- 
ckiairie,  Bd.  vii,  Heft  iii,  1877. 


GUDDEN'S  ATROPHY  METHOD.  9 

plete  absence  of  the  posterior  root  zone  on  the  injured  side. 
The  posterior  part  of  the  lateral  column  is  also  very  slightly 
reduced  in  size. 

T\\^  gray  substance  shows  the  greatest  atrophy.  At  level 
of  greatest  lesion,  the  anterior  gray  horn  is  much  reduced 
in  size,  and  has  lost  its  quadrangular  shape,  and  is  barren  of 
ganglion  cells.  Higher  up  the  posterolateral  group  of 
cells  is  preserved,  especially  in  the  cord  of  the  animal  whose 
sciatic  had  been  simply  divided.  Some  ganglion  cells  on 
the  side  opposite  the  injury,  those  sending  cylinder-axis 
processes  toward  the  commissura  anterior,  must  have  per- 
ished, for  they  are  fewer  in  number  than  the  same  cells  on 
the  injured  side  (evidence  of  crossed  origin  of  some  fibres  of 
sciatic).  The  posterior  horn  on  the  injured  side  is  about 
one  third  smaller  than  normal ;  still  it  contains  many  small 
ganglion  cells,  and  the  difference  is  mainly  in  the  fibre-sys- 
tem. The  substantia  gelatinosa  is  much  atrophied,  but 
shows  only  a  small  reduction  in  the  number  of  its  cells. 
The  two  commissures  are  reduced  in  size,  the  posterior 
more  so. 

Essentially  similar  lesions  were  found  in  the  cervical 
spinal  cord  of  a  rabbit  whose  brachial  plexus  had  been  ex- 
tracted. 

IX. — Nuclei  of  the  cranial  nerves.^ 
From  personal  examination  of  specimens. 

NN.  iii  and  iv.  Expt. — Extirpation  of  the  eyeball  in  a  newly- 
born  rabbit,  with  careful  extraction  of  orbital  nerves. 

Result  :  Atrophy  in  various  parts  of  optic  apparatus,  as  de- 
scribed supra  ;  complete  atrophy  of  NN.  iii,  iv,  and  vi.  Series  ot 
trans-sections  enable  us  to  study  the  deeper  atrophy  of  the  nuclei 
of  these  nerves. 

'  Prof.  V.  Gudden  has  made  no  systematic  publication  of  these  valuable 
results.  Here  and  there  in  his  papers  he  refers  to  the  facts  which  have  long 
been  known  to  him  ;  many  prior  to  1872,  as  shown  by  their  citation  in  Kon- 
dracki's  Zurich  thesis. 


lO  E.  C.  SEGUIN. 

I.  N.  iii.'  Nucleus  in  well-known  location,  caudad  of 
lobus  opticus  and  dorsad  of  fasciculus  longitudinalis  poste- 
rior. By  Gudden's  method  the  nucleus  is  made  out  to  be 
triple. 

[a)  A  fronto-ventral  nucleus  lying  upon  the  fasc.  long, 
post.,  and  giving  origin  to  fibres  which  pass  ventrally  in  a 
straight  direction. 

ib)  A  caudo-ventral  nucleus,  partly  dorsad  of  («),  overlap- 
ping it  somewhat,  but  also  extending  (in  its  caudal  part) 
down  to  the  fasc.  long.  post.  This  cell-group  also  gives  rise 
to  direct  vertical  fibres. 

if)  A  caudal  nucleus  lying  dorsad  of  (<^),  not  reaching  the 
level  of  the  fasc.  long,  post.,  and  separated  from  the  nucleus 
of  N.  iv  by  a  distinct  barren  interval.  This  contains  and 
gives  origin  to  decussated  and  horizontally  coursing  fibres. 

In  a  normal  preparation,  a  horizontal  section  made  just 
dorsad  of  the  fasc.  long.  post,  shows  cells  of  nuclei  (i^)  and  (<5) 
and  cross-cut  nerve  fibres.  One  made  further  dorsad,  pass- 
ing through  nucleus  {c\  shows  cells  and  mostly  horizontally 
running  nerve  fibres. 

Similar  sections  from  an  animal  experimented  upon  as 
described  above  show^  :  the  ventral  section^  absence  of 
fibres  and  cells  on  the  same  side  as  the  injury  ;  the  dorsal 
section,  on  the  contrary,  exhibits  atrophy  (absence)  of  cells 
and  horizontal  fibres  on  side  opposite  the  injury. 

The  decussation  of  the  fibres  of  N.  iii  occurs  mostly  by 
the  lateral  fibres  of  the  root,  which  pierce  the  ventral  nuclei, 
then  turn  pretty  sharply  mediad  and  decussate  with  their 
homologues  to  connect  with  cells  in  the  dorsal  nucleus  of 
the  opposite  side.  A  few  fibres  decussate  to  reach  this 
nucleus  through  the  raphe.  The  large  majority  of  the  root- 
fibres  of  N.  iii,  constituting  the  medial  roots,  arise  from  {a) 
and  {p)  and  pass  out  directly. 

'  Vide  a  short  communication  in  Mittheilungen  der  Morphol. -Physiol. 
Gesellschaft  zu  Munchen,  in  Miinchner  Aerztlichen  Intelligenzblatt,  1883. 


GUDDEN'S  ATROPHY  METHOD.  II 

Prof,  von  Gudden  anticipates  that  by  a  better  method  of 
extirpation  of  single  ocular  muscles  with  their  attached 
nerve  filaments,  we  may  yet  be  able  to  define  a  greater  dif- 
ferentiation of  cell-groups  in  the  oculomotor  nuclei.  In 
this  connection  it  is  well  to  mention  that  in  studying  the 
atrophied  N.  iii  nuclei,  the  displacement  produced  by 
atrophy  of  the  two  ventral  nuclei  on  the  side  of  the  injury 
must  be  borne  in  mind.  In  consequence  of  the  virtual  void 
thus  caused,  the  dorsal  nucleus  is  displaced  downward  or 
ventrally,  and  the  fasc.  long.  post,  in  a  dorso-mediad  direc- 
tion. Prof.  Gudden  has  long  ago  appreciated  and  called 
attention  to  this  source  of  error  in  studying  sections  from 
regions  atrophied  by  his  method.  We  will  see  other 
illustrations  of  this  further  on  {vide  corpus  mammilare  and 
von  Monakow's  researches  on  the  thalamus). 

2.  N.  iv.  Its  nucleus  lies  caudad  of  the  caudal  nucleus  of 
N.  iii,  and  extends  down  to  the  fasc.  long.  post.  In  pathologi- 
cal brains,  sagittal,  horizontal,  and  trans-sections  show  that 
the  atrophy  involves  only  one  nucleus,  always  the  one  on 
the  side  opposite  the  injury.  Consequently  N.  iv  has  a 
simple  origin,  and  its  root-fibres  wholly  decussate. 

3.  N.  V.'  Two  series  of  preparations  were  shown  me  : 
I.  Trans-sections  from  the  nerve  centres  of  a  rabbit  whose 
trigeminus  on  one  side  had  been  cut  between  the  pons 
Varolii  and  the  ganglion  Gasserii ;  the  operation  was  done 
by  the  old  intracranial  method,  and  was  not  entirely  suc- 
cessful. In  the  sections,  a  partial  atrophy  of  the  ascending 
root  can  be  traced  frontad  from  a  point  between  the  second 
and  third  cervical  nerve  to  the  level  of  exit  of  root.  The 
descending  root  and  its  peculiar  cells  also  show  marked 
atrophy.  The  motor  nucleus  and  root  are,  on  the  contrary, 
well  preserved.  2.  Series  of  trans-sections  from  the  nervous 
centres  of  a  calf  presenting  extensive  malformations  and 
atrophies  of  the  brain. 

*  Unpublished. 


12  E.  C.  SEGUIN. 

The  principal  lesions  presented  by  this  brain,  as  exhibited 
in  a  drawing  of  its  basis,  were:  (i)  absence  of  right  olfac- 
tory nerves  and  tractus  (bulb  partly  preserved) ;  (2)  com- 
plete absence  of  both  optic  nerves  and  tractus,  with  pres- 
ervation of  the  commissura  inferior;  (3)  partial  atrophy  of 
right  N.  iii  ;  (4)  preservation  of  both  NN.  iv  ;  (5)  root  of 
right  N.  V  seems  totally  atrophied,  while  its  ganglion  and 
peripheral  branches  are  preserved  ;  (6)  absence  of  both  NN. 
vi ;  (7)  preservation  of  both  NN.  vii  and  of  the  other  nerves 
caudad 

Sections  from  the  level  of  second  cervical  nerve  to  that 
of  lobus  opticus  examined  :  On  the  right  side  there  is  com- 
plete absence  of  the  ascending  (spinal)  root  of  N,  v 
throughout  its  entire  extent.  The  motor  nucleus  and  root 
are  likewise  completely  absent.  Of  the  descending  root  a 
few  cells  exist,  and  a  few  fibres  from  them  can  be  traced 
caudo-ventrad  toward  the  exit  region  of  nerve-trunk. 

From  these  specimens  (and  others)  Gudden  is  willing  to 
recognize  only  three  roots  of  the  trigeminus,  two  sensory 
and  one  motor.  The  other  roots,  as  given  by  Meynert  and 
others,  he  regards  as  imaginary.' 

4.     N.  vi.     ExPT. — Described  in  paragraph  on  N.  iii.     Trans- 

'  In  this  connection  it  may  be  interesting  to  refer  to  von  Gudden's  numer- 
ous and  ingenious  experiments  on  the  question  of  the  trophic  function  of  the 
trigeminus.  Some  of  these  are  already  quite  old  and  are  cited  by  Kondracki 
in  his  thesis  in  1872  (E.  Kondracki  :  Ueber  die  Durchschneidung  des  Nervus 
trigeminus,  Zurich),  but  although  better  than  Snelling's  they  are  unknown. 
He  admitted  the  fact  that  after  section  of  the  trigeminus  ulceration  of  the 
cornea  and  other  changes  of  nutrition  occurred  in  the  eye.  He  took  newly- 
born  rabbits  and  caused  adhesion  of  the  lids  by  operation  (artificial  ankylo- 
blepharon). When  this  was  entirely  healed  he  cut  the  trigeminus  by  the  intra- 
cranial method.  Opening  the  lids  ten  or  fifteen  days  later  he  invariably  ob- 
tained normal  coniese.  Consequently  he  held  the  eye-lesions  following  section 
of  N.  V  to  be  traumatic  in  origin.  More  recently  (oral  communication)  von 
Gudden  has  operated  by  cutting  the  optic  nerve  behind  the  eyeball  with  the 
least  possible  injury  to  other  parts  within  the  orbit.  In  this  operation  the 
ciliary  nerves  are  cut,  and  besides  blindness  there  is  anesthesia  of  the  cornea. 
But  the  lids  retain  their  sensibility  and  by  reflex  action  continue  to  protect  the 
eye  from  injury  and  dirt  ;  the  cornea  remains  clear.  Kondracki  also  refers  to 
operations  on  peripheral  nerve-trunks  after  which,  by  care  and  cleanliness,  the 
skin  of  the  foot  remained  free  from  the  falsely  so-called  trophic  changes. 
Gudden  was  not  aware  that  long  before  Brown-Sequard  had  demonstrated  f&cts 
like  the  last,  showing  ulcerations  after  nerve-sections  to  be  traumatic. 


G  UDDEN '  S  A  TROPH  Y  ME  THOD.  1 3 

sections  show  complete  absence  of  trunk  of  nerve  in  the  medulla, 
and  total  atrophy  of  the  cell-group  laterad  of  genu  of  facial  nerve. 
In  the  calf's  brain  above  described,  while  the  facial  nerves  and 
nuclei  are  well  preserved,  there  is  no  trace  of  the  fibres  and 
nucleus  of  NN.  vi.     In  neither  case  do  any  cells  remain. 

Consequently  the  origin  of  the  abducens  nerve  is  simple 
and  direct. 

5.  N.  vii.  ExPT. — In  the  newly-born  rabbit  the  facial  nerve  is 
extracted  from  the  Fallopian  canal.  If  the  operation  is  well  done 
a  long  piece  of  the  nerve  is  brought  away. 

Results  :  Complete  absence  of  extra-  and  intra-bulbar  root  of 
nerve  on  operated  side  ;  the  ventral  aspect  of  the  medulla  is  a 
little  flattened.  Sections  show  absence  of  root-fibres  ;  the  site  of 
genu  is  vacant,  and  no  cells  can  be  found  in  the  so-called 
"  lower  nucleus,"  the  three-grouped  nucleus  (rabbit)  in  the  ventral 
aspect  of  the  medulla.  On  the  other  hand,  the  nucleus  under  the 
genu  of  the  nerve,  near  the  floor  of  the  fourth  ventricle,  is  abso- 
lutely normal  ;  comparison  with  a  normal  nucleus  shows  that  no 
cells  are  absent. 

Consequently  the  facial  nerve  has  only  one  nucleus — in 
opposition  to  the  teaching  of  nearly  all  anatomists  who  have 
seen  fibres  of  this  nerve  arise  from  the  nucleus  under  its 
genu.  Even  so  recent  an  authority  as  Spitzka '  elaborate^ 
ly  describes  this  double  origin  of  N.  vii. 

In  estimating  the  full  value  of  this  experiment,  the  re- 
sult of  operation  upon  N.  vi  must  also  be  borne  in  mind  : 
the  two  experiments  mutually  support  one  another,  and 
their  agreement  (in  a  large  number  of  experiments  by  Gud- 
den  and  several  of  his  pupils)  renders  an  error  extremely 
unlikely. 

6.  N.  viii.  As  yet  it  has  been  impossible  to  complete 
an  experiment  upon  this  nerve,  because  of  the  severe  rota- 
tory movements  and  death  by  exhaustion  which  follow 
its  section  or  extraction.  Still,  some  important  negative 
conclusions  have  been  reached  indirectly.     First,  it  has  no 

'  Contributions  to  Encephalic  Anatomy,  pp.  85-87,  yournal  of  Nemous 
and  Mental  Disease,   April,    1880. 


1 4  E.  C.  SEGUIN. 

connection  with  the  so-called  external  auditory  or  Deiters' 
nucleus,  for  a  proof  of  which  statement  see  Monakow's  ex- 
periment on  corpus  restiforme,  p.-s^;  second,  in  Gudden's 
removal  of  one  cerebellar  hemisphere,  the  nerve  and  its  nu- 
cleus were  perfectly  normal. 

7.  N,  X.*  ExPT. — Extraction  of  central  end  of  nerve  and  its 
ganglia  in  rabbits. 

Results  :  Atrophy  of  well-known  sub-ependymal  nucleus,  dorso- 
laterad  of  nucleus  of  hypoglossus.  There  is  also  complete  atrophy 
of  a  group  of  large  cells  lying  ventrad  of  intra-bulbar  root  of  the 
nerve,  and  mediad  of  the  so-called  nucleus  lateralis  (which,  as 
shown  supra,  is  one  of  the  origins  of  the  corpus  restiforme.)  The 
tri-neural  fasciculus  (Spitzka's  good  name  for  the  " gemeinschaftltche 
aufsteigetide  Wiirzel  des  seitlichen  gemischten  Systetns  "  of  Meynert) 
is  also  decidedly  atrophied  on  the  operated  side. 

8.  N.  xi.  A  number  of  apparently  successful  extraction  ex- 
periments have  been  made  on  this  nerve,  but  the  brains  have  not 
yet  been  cut. 

9.  N.  xii.^  ExPT. — Extraction  (extra-spinal)  of  the  hypo- 
glossal in  a  rabbit  from  five  to  eight  days  old. 

Results  :  Complete  atrophy  of  the  cells  of  the  sub-ependymal 
medial  nucleus  of  hypoglossus,  and  absence  of  intra-bulbar 
rootlets.  In  the  series  of  sections  which  I  examined,  there  re- 
mained a  few  fibres  and  cells  of  the  most  caudal  part  of  the 
nucleus,  from  a  slight  incompleteness  in  the  operation.  The 
ganglion  cells  dorsad  of  the  atrophied  nucleus,  those  of  the  oppo- 
site hypoglossal  nucleus,  and  the  olives,  were  perfectly  normal. 

Hence  the  origin  of  this  nerve  is  simple  and  direct. 

These  results  are  very  instructive.  They  show,  in  an  ap- 
parently convincing  manner,  that  nearly  all  the  cranial 
nerves  have  a  much  simpler  origin  than  most  anatomists 
— especially  those  who  allow  physiological  considerations 
to  warp  their  observation — describe.  Yet  the  one  nerve 
which  nearly  all  observers  describe  as  having  a  simple 
direct  origin — N.  iii — is  conclusively  proved  by  most 
beautiful  experiments  to  have  a  highly  complex    nucleus, 

'  Unpublished. 

'  Idem,  but  referred  to  briefly  in  several  papers. 


GUD DEN'S  ATROPHY  METHOD.  15 

and  to  arise  by  both  direct  and  crossed  fibres.  Even  if 
we  are  not  prepared  to  admit  that  these  experiments  of 
von  Gudden  absolutely  settle  the  question  of  the  origin 
of  the  cranial  nerves,  yet  the  results  are  sufificiently  clear 
and  constant,  it  seems  to  me,  to  merit  the  attention  of 
anatomists,  and  to  serve  in  some  measure  as  a  control 
upon  the  mere  study  of  sections  from  normal  nerve 
centres. 

X. — Fasciculus  longitiidinalis  posterior. 

There  are  no  experiments  directly  bearing  upon  this  part, 
but  from  a  consideration  of  some  of  the  specimens  above 
referred  to  and  some  others,  important  negative  conclusions 
can  be  reached. 

It  is  generally  taught  by  anatomists  that  this  fasciculus  is 
directly  connected  with  the  nuclei  of  the  motor  cranial 
nerves,  more  especially  those  of  NN.  iii  and  iv,  serving  per- 
haps as  a  means  of  associating  or  coordinating  their  action. 
That  this  is  not  so,  that  it  is  an  example  of  hypothetical 
anatomy,  is  shown  by  the  following  facts. 

1.  In  sections  exhibiting  atrophy  of  NN.  iii  and  iv,  the 
fasc.  long.  post,  are  of  equal  and  normal  size,  even  when  one 
is  displaced  somewhat,  as  in  atrophy  of  the  oculomotorius. 

2.  In  the  mole,  whose  entire  optic  apparatus,  including 
NN.  iii  and  iv,  is  undeveloped  and  as  good  as  absent,  there 
is  a  well-developed  fasc.  long.  post. 

XL — Ganglion  interpeduncular e. ' 
This   ganglion  is  a  distinct   external   protuberance  in  rab- 
bits, cats,''  and   dogs  ;  in  the   monkey  (Hapale),  and  in  man 
it  lies  concealed  in  the  wall  of   the   foramen  coecum,  but  is 

'  Gudden  ;  Mittheilungen   uber  das  Ganglion   Interpedunculare. —  WesiphaVs      ^  /"^ 
Archiv,  Bd.  xi,  Hft.  2,  i88o.  ,  _^ 

"This   part  is  not  named,  figured,   or   indexed  by  Wilder,  op.  cit.  J    The     ./M.  i-^-^ 
ventral  origin  of  the  fasciculus  Meynerti  was  jointly  discovered  by  Gudden  and      /_    /^ 
Forel  prior  to  1872,  but  not  by  Gudden's  method. '^^,  ^^^  (j 


1 6  E.  C.  SEGUIN. 

not  to  be  confounded  with  the  substantia  perforata  posterior. 
It  consists  mainly  of  small  round  or  spindle-shaped  ganglion 
cells,  the  smallest  of  which  are  very  similar  to  "  nuclei  " 
of  the  neuroglia.  It  also  contains  some  angular  ganglion 
cells.  The  little  nests  described  by  Forel  (Haubenregion, 
WestphaV s  Archiv,  Bd.  vii,  p.  393)  are  really  made  up  of 
most  delicate  amyelinic  nerve  fibres. 

In  horizontal  sections  of  normal  rabbit's  brain,  the  G.  I. 
lies  caudad  of  the  foramen  coecum,  between  the  lemnisci 
(Schleife).  From  its  frontal  extremity  issue  the  two  fascic- 
uli Meynerti,  and  laterad  of  these  are  cross-sections  of 
bundles  of  N.  iii,  and  longitudinal  sections  of  the  pedun- 
culus  corporis  mammillaris  {vide  infra).  A  little  frontad 
and  quite  laterad  of  the  foramen  coecum  are  cross-sections 
of  the  tractus  peduncularis  transversus. 

ExPT. — Removal  of  one  ganglion  habenulse  in  a  rabbit  a  few 
days  old. 

Results  :  Complete  atrophy  of  corresponding  fasciculus  Mey- 
nerti, of  its  point  of  entrance  into  ganglion  interpedunculare,  and 
of  the  ganglion  itself  on  both  sides  of  the  median  line.  No 
atrophy  of  cells  observed.  It  is  not  stated  whether  fibres  of 
origin  of  fasc.  M.  decussate  or  not  in  the  ganglion,  but  from  the 
illustration  accompanying  the  article,  it  would  seem  that  they 
did. 

XII. —  The  corpus  inammillare? 

Von  Gudden  describes  the  external  appearance  and 
general  configuration  of  the  C.  M.  in  rabbits,  cats,  dogs, 
monkey  (Hapale),  and  in  man.  Each  animal  presents 
some  difference  in  external  configuration  of  c.  M.  The 
rabbit  presents  lateral  accessory  eminences,  which  are  the 
lateral  ganglia. 

Microscopic  examinations  (trans-sections),  however,  show 
that  in  all  animals  there  are  two  sets  of  nuclei,  a  medial 
and  a  lateral  on  either  side. 

'  Gudden  :  Beitrag  zur  Kentniss  des  Corpus  Mammillaie  und  der  sogen- 
annten  Schenkel  des  Fornix. —  WestphaV s  Archiv,  Bd.  xi,  Hft.  2,  1880. 


G UDDEN  '  S  A  TROPH  Y  ME  THOD.  1 7 

/  I.  The  lateral  ganglion  of  c.  M.  It  contains  large  gang- 
lion waiUc.  From  its  lateral  part  arises  a  fasciculus,  the 
pedunculus  corporis  mammillaris.  In  the  rabbit  this  fascic- 
ulus lies  mediad  of  crus  cerebri  ;  most  N.  iii  fibres  pass  out 
through  it.  The  ganglion  interpedunculare  and  the  begin- 
ning of  fasciculus  Meynerti  lie  mediad  of  the  ped.  corp.  mam. 
It  tends  dorso-latero  caudad  to  enter  the  pons  Varolii.  The 
columnar  fornicis  lie  mediad  of  it.  It  almost  joins  the  lem- 
niscus (Schleife),  but  can  be  distinguished  from  it  by : 

{a)  Its  larger-sized  nerve  fibres,  which  can  be  traced 
ventro-laterad  of  the  lemniscus,  through  the  trapezium, 
into  the  medulla  oblongata,  as  far  caudad  as  the  olives. 

{b)  By  any  experiment  which  causes  atrophy  of  the 
pyramidal  tract  iindc  p.  238),  such  as  removal  of  the  frontal 
part  of  the  brain,  or  of  one  hemisphere.  On  examining 
trans-sections  from  such  a  case,  one  can  trace,  caudad  of 
the  commissura  anterior,  atrophy  of  the  fine  fibre  system 
of  the  lemniscus,  as  well  as  of  the  pyramidal  tract  proper 
on  the  side  of  the  injury.  The  large  fibres  of  the  ped. 
Corp.  mam.  ventro-laterad  of  the  absent  lemniscus,  between 
it  and  the  site  of  the  pyramidal  tract,  are,  however,  pre- 
served. In  passing  through  the  trapezium  (never  ventrad 
of  it),  it  becomes  more  medial  and  approaches  its  fellow  : 
in  the  trapezium  the  fibres  are  somewhat  scattered,  but 
caudad  of  it  they  once  more  unite  to  form  a  compact 
bundle  lying  dorsad  of  the  pyramid  (which  is  mostly  made 
up  of  fine  fibres).  In  the  region  of  the  olives  the  fascic- 
ulus tends  more  dorsad  and  is  lost. 

Conclusion  :  the  lateral  ganglion  of  C.  M.  is  unconnected 
with  the  hemisphere. 

2.  Medial  ganglion,  made  up  of  smaller  cells.  Two  fasciculi 
arise  from  it,  viz.,  the  fasciculus  Vicq  D'  Azyr  (Meynert's 
radix  ascendens  of  columna  fornicis)  and  the  fasciculus  ad 
tegmentum  {Haubenbiindcl^. 


15  E.   C.  SEGUIN. 

{a)     Fasciculus  ad  tegmentum.     Vide  special  paragraph, 

{b)     Fasciculus  Vicq  D'  Azyr. 

ExpT. — After  removal  of  one  hemisphere  (rabbit)  this  fasci- 
culus and  the  medial  ganglion  of  c.  M.  undergo  partial  atrophy. 
Refers  to  illustrations  by  Cruveilhier,  Van  der  Kolk,  and  other, 
of  unsymmetrical  (atrophied)  human  brains  showing  atrophy  of 
one  of  the  two  eminences  of  the  c.  m. 

ExpT. — Removal  of  one  hemisphere  and  of  the  frontal  part  of 
the  thalamus. 

Results :  Complete  atrophy  of  fasc.  Vicq  D'  Azyr  and  of  the 
ventral  part  of  medial  nucleus  of  C.  m. 

Conclusion  :  The  fasc.  Vicq  D'  Azyr  arises  from  the 
ventral  part  of  the  medial  ganglion  of  C.  M.,  and,  extending 
dorso-frontad  (in  rabbit),  is  distributed  to  the  nucleus 
anterior  of  the  thalamus  (tuberculum  anterius).  There  it 
also  enters  into  indirect  connection  with  fibres  of  the 
corona  radiata,  which  extend  to  the  cortex  cerebri  (to 
vicinity  of  motor  area,  according  to  Von  Monakow's  ex- 
periments— vide  i?ifrd). 

XIII . — Connections  of  the  coluinncs  fornicis.^ 

ExPT. — Removal  of  one  hemisphere  and  section  or  removal  of 
both  Ammon's  horns. 

Results  :  Trans-sections  show  complete  atrophy  (absence)  of 
both  columnas  fornicis  ;  the  fasciculus  Vicq  D'  Azyr  is  reduced 
in  size  on  the  side  of  absent  hemisphere. 

ExpT. — Removal  of  one  hemisphere  without  injury  to  cornu 
Ammonis. 

Results  :  Columns  fornicis  normal  ;  fasciculus  Vicq  D'  Azyr 
somewhat  reduced  in  size  on  operated  side. 

ExPT. — Incision  of  one  hemisphere  and  section  or  laceration 
of  fimbria  on  one  side  dorsad  of  commissura  anterior. 

Results  :  Disappearance  of  columnae  fornicis  on  operated  side  ; 
very  slight  reduction  in  size  of  fasc.  Vicq  D'  Azyr. 

Dr.  Ganser's    Expt. — After  removal    of  one  -  eyeball,   a  fine 

"  Beitrag  zur  Kenntniss  des  Corpus  Mammillare  unci  der  sogenannten 
Schenkel  des  Fornix. —  Westphal's  Arckiv,  Bd.  xi,  Hft.  2,  1880. 


GUDDEN'S  ATROPHY  METHOD.  .  1 9 

forceps  was  introduced  through  the  foramen  opticum  in  the  direc- 
tion of  the  chiasm,  with  the  intention  of  destroying  the  tractus 
opticus  on  one  side.  Besides  this,  however,  a  slight  cut  was  made 
in  the  tuber  cinereum  which  severed  one  columna  fornicis. 

Results  :  Complete  atrophy  of  injured  columna  fornicis  frontad 
of  corpus  mammillare  ;  caudad  the  atrophy  could  be  traced  be- 
hind the  c.  M.  to  the  point  where  the  col.  fornicis  decussates  with 
its  homologue  {inde  next  section)  to  the  side  opposite  the  injury, 
in  the  central  gray  matter.     The  fasc.  Vicq  D'  Azyr  were  normal. 

These  experiments  show  that  the  columnae  fornicis  enter 
into  the  formation  of  (are  continuous  with)  the  fimbria, 
fornix,  and  cornu  Ammonis. 

They  also  prove  in  the  most  positive  manner  that  there 
is  no  continuity  between  the  columnse  fornicis  and  the 
fasciculi  Vicq  D'  Azyr,  and  that  these  fasciculi  do  not  form 
a  genu  or  loop  in  or  around  the  corpus  mammillare,  as 
claimed  by  Meynert.' 

XIV. — Composition  of  the  colunmcB  fornicis. 

This  is  much  more  complex  than  is  taught  in  works  on 
nervous  anatomy,  and  an  approach  to  an  exact  solution  has 
only  been  reached  by  von  Gudden  within  the  last  year, 
after  a  study  of  many  years,  embracing  the  performance  of 
numerous  experiments. 

To  Ganser,  his  very  able  and  ingenious  collaborator,  we 
owe  the  first  and  principal  step  in  this  series  of  discoveries, 
viz.:  the  experimental  determination  of  the  passage  of  the 
columna  fornicis  through  the  corpus  mammillare  (contrary 
to  all  previous  writers,  who  taught  that  it  arose  from  the  C. 
M.),  and  of  its  origin  further  caudad  and  dorsad,  in  the  cen- 
tral gray  surrounding  the  third  ventricle. 

In  1880  '  von  Gudden  published  an  article  upon  the  cor- 
pus mammillare  and  columnae  fornicis,  in  which  he  claimed 
the  demonstration  of  two  additional  fasciculi  of  the  columna 

'Strieker:    "  Manual  of   Histology,"  Am.   ed.,  pp.  691-2,  fig.  269.     New 
York,  1872. 
"^  Op.  cit. 


E.  C.  SEGUIN. 


fornicis,  besides  the  well-known  bundle  studied  by  Ganser. 
In  the  past  year  he  has  found  still  a  fourth  bundle  in  this 
system,  but  has  not  made  the  discovery  public.  Conse- 
quently, instead  of  giving  an  abstract  of  the  paper  of  1880, 
I  shall  give  a  r^sumtf  oi  what  Prof.  Gudden  demonstrated  to 
me,  and  of  his  explanations. 

He  now  considers^the  so-called  columna  fornicis  {Fornix- 
sdule)  consist  of  four  fasciculi,  viz. : 

1.  A  ventral  crossed  fasciculus. 

2.  A  dorsal 

3.  A  dorsal  direct  fasciculus. 

4.  A  ventral     " 

I.  The  ventral  crossed  bundle  is  the  one  long  known  as 
the  columna  fornicis  in  its  passage  through  the  tuber  cine- 
reum  to  the  corpus  mammillare  (Meynert's  radix  descendens 
fornicis).  Its  true  origin  and  course  were  discovered  by 
Ganser  in  1878  by  an  experiment  described  on  p.^JJ*  The 
origin  he  found  to  be  in  the  central  gray  near  the  third  ven- 
tricle, but  not  from  any  distinct  cell-group.  In  most  ani- 
mals these  fibres  of  origin  are  scattered,  and  their  course  is 
difficult  or  even  impossible  to  make  out,  but  in  rabbits 
(with  a  few  individual  exceptions),  in  mice,  and  moles  the 
fibres  are  aggregated  into  considerable  fasciculi,  so  that 
carmine,  gold,  and  osmic  preparations  exhibit  distinct  pict- 
ures. As  seen  in  the  typical  rabbit  the  fine  bundles  com- 
ing from  the  central  gray  run  ventro-frontad  ;  they  are 
mediad  of  the  fasciculi  Meynerti.  At  a  point  caudad  and 
dorsad  of  the  medial  ganglia  of  the  corpus  mammillare  these 
fine  bundles  completely  decussate  ;  they  now  form  a  large 
fasciculus  on  either  side,  which  curves  around  the  medial 
ganglion  of  the  c.  M.,  passes  frontad  between  it  and  the  lat- 
eral ganglion.  It  apparently  issues  from  the  frontal  aspect 
of  the  c.  M.  into  the  tuber  cinereum,  takes  a  direction  dorso- 
latero-frontad  to  a  level  dorsad  of  the  commissura  anterior, 


G UDDEN 'S  Al ROPH Y  ME THOD.  2 1 

where  it  enters  into  the  formation  of  the  root  of  the  fornix. 

2.  The  dorsal  crossed  bundle  joins  No.  i  at  a  point  fron- 
tad  of  the  tuber  cinereum.  It  is  demonstrated  by  the  pre- 
viously cited  experiment  of  removal  of  one  hemisphere  and 
of  its  cornu  Ammonis  without  injury  to  the  root  of  the  fornix 
(region  where  columnse  fornicis  enter  fornix).  In  a  series 
of  trans-sections  from  such  a  brain,  one  sees,  as  stated  supra, 
that  fasciculus  No.  i  is  completely  absent  caudad  of  C.  M. 
in  it,  and  in  the  tuber  cinereum  ;  but  in  the  sections  frontad 
of  this  point,  at  the  level  of  the  commissura  anterior,  a  bun- 
dle of  transversly-cut  nerve  fibres  is  seen  close  to  the  site  of 
the  atrophied  columna  fornicis — just  mediad  of  it.  These 
fibres  are  pale  ;  they  have  taken  up  much  less  carmine  than 
those  of  the  normal  fasciculus  No.  i  on  the  opposite  side. 
Still  further  frontad,  over  the  commissura  anterior,  these 
fibres  diverge  toward  the  median  line,  cross  it,  and  enter 
the  fornix  of  the  opposite  non-operated  side.  Indeed, 
without  special  preparation,  after  this  experiment,  by  turn- 
ing what  remains  of  the  fornix  over  frontad,  it  is  easy  to 
see  with  the  naked  eye  a  fasciculus  passing  from  the  normal 
half  of  the  fornix  ventrad  toward  the  median  line.  In  the 
sections  it  is  also  evident  that  this  fasciculus  (No.  2)  is  ab- 
sent in  the  column  opposite  the  injury,  while  its  main 
bundle  (No.  i)  is  present. 

3.  The  dorsal  direct  bundle  is  made  evident  by  Cau- 
ser's experiment  of  wound  in  the  tuber  cinereum  p.  o^y^ 
The  inferior  fasciculus  (No.  i)  is  absent  on  one  side  in  the 
sections,  but  dorsad  of  the  commissura  anterior  there  ap- 
pears near  the  site  of  the  absent  bundle  a  round  section  of 
fibres.  These  can  be  traced  caudad  in  the  series  of  sections  ; 
it  spreads  latero-dorsad,  describing  a  curve  with  convexity 
outward,  to  reach  the  dorso-lateral  part  of  the  thalamus, 
where  it  seems  connected  with  a  cell-group.  It  may,  how- 
ever, have  an  origin  at  a  point  further  ventrad  in  the  curve, 


22  E.  C.  SEGUIN. 

where  there  is  a  nest  of  larger  cells.  In  this  course  the 
fibres  of  fasciculus  No.  3  enter  into  the  formation  of  the 
stratum  zonale.  As  seen  dorsad  of  the  commissura  ante- 
rior its  fibres  are  smaller  than  those  of  fasciculi  i  and  2. 
After  removal  of  one  Ammon's  horn  it  undergoes  atrophy 
on  the  same  side  as  the  injury.  If  von  Gudden  were  sure 
that  this  fasciculus  (No.  3)  ended  in  the  above-mentioned 
cell-group  in  the  thalamus,  he  would  call  it  the  thalamic  root 
of  the  fornix,  but  he  now  prefers  to  call  it  the  dorsal  direct 
bundle. 

4.  The  ventral  direct  bundle.'  After  Ganser's  experi- 
ment in  sections  through  the  tuber  cinereum,  two  or  three 
little  stained  fasciculi  (cross-cut)  are  seen  to  join  the 
columna  fornicis,  or  on  the  operated  side  to  tend  toward  its 
site.  Their  ultimate  course  frontad  is  unknown,  but  it  is 
certain  that  they  undergo  atrophy  on  the  same  side  as  the 
injury  when  the  cornu  Ammonis  is  removed  on  one  side. 
Caudad  the  small  bundles  can  be  traced  in  a  direction 
ventro-medio-dorsad  into  the  central  gray  matter  frontad  of 
corpus  mammillare  :  a  distinct  nucleus  has  not  been  ob- 
served. 

Prof.  V.  Gudden  believes  that  bundles  i  and  4  con- 
tribute to  form  that  part  of  the  fornix  which  lies  under  the 
corpus  callosum  and  is  known  as  the  longitudinal  fornix. 
Bundles  2  and  3  diverge  and  take  a  dorso-laterad  course  in 
the  fornix. 

The  taenia  thalami^ crosses  bundle  No.  3,  passes  caudad  of 
it  without  giving  it  any  fibres.  This  is  distinctly  seen  in 
such  atrophy  preparations  as  involve  atrophy  of  the  entire 
columna  fornicis  :  the  cross-section  of  the  taenia  has  the 
same  diameter  on  either  side.  Neither  have  any  of  the  prep- 
arations afforded  evidence  of  a  connection  between  the 
columna  fornicis  and  the  stria  cornea. 
*  Unpublished. 


G UDDEN ' S  A  TROPH  Y  ME  THOD.  2 3 

XV. — Fasciculus  ad  tegmentum  {Haubenbiindet)^ 

This  was  partly  described  by  Prof,  von  Gudden  in  his 
paper  on  the  corpus  mammillare  (1880).  He  then  correctly 
described  its  course,  but  its  true  origin,  and  more  especially 
its  termination  in  a  distinct  ganglion  in  the  tegmentum, 
were  not  discovered  until  this  year,  and  I  have  the  privilege 
of  first  making  the  facts  public. 

Origin  of  the  fasciculus.  In  sections  from  a  rab- 
bit which  had  undergone  removal  of  one  hemisphere 
together  with  the  anterior  part  of  the  thalamus,  the  fascic- 
ulus Vicq  D'  Azyr  is  completely  absent  on  the  operated 
side,  and  the  medial  ganglion  of  the  corpus  mammillare  to 
a  great  extent  atrophied.  However,  one  sees  in  the  trans- 
sections,  a  fasciculus  arising  from  the  remains  of  the  medial 
ganglion  of  the  corpus  mammillare ;  it  extends  a  little  way 
dorsad,  then  turns  abruptly  ventro-caudad  to  enter  the  teg- 
mentum. 

In  a  very  successful  (z.^.,  in  the  right  plane)  horizontal  sec- 
tion from  a  normal  rabbit  brain  the  horizontal  course  of  the 
fasciculus  can  be  traced  a  long  way.  In  the  frontal  part  of 
such  a  preparation  are  the  commissura  anterior  and  cross- 
sections  of  the  columnae  fornicis  ;  then,  proceeding  caudad, 
in  the  median  line  the  slit-like  opening  of  the  third  ven- 
tricle ;  on  either  side  of  this  a  large  bundle  is  seen  in  cross- 
section,  the  fasciculus  Vicq  D'  Azyr  ;  from  this  a  bundle  of 
fibres  diverges  caudad,  tending  toward  the  median  line  ;  it 
passes  mediad  of  another  large  bundle  seen  in  cross-sec- 
tion, viz.:  the  fasciculus  Meynerti ;  a  little  further  caudad  it 
lies  mediad  of  the  emerging  roots  (cross-cut)  of  N.  iii, 
and  finally  is  lost  very  near  the  median  line,  just  ventrad  of 
the  fasciculus  longitudinalis  posterior. 

The  exact  caudad  connection  (termination)  of  the  fasc.  ad 
tegmentum  was  ascertained  by  the  following  experiment. 
'  Unpublished. 


24  E.  C.  SEGUIN. 

By  passing  a  very  delicate  knife  vertically  through  the  cor- 
pus callosum  to  the  base  of  the  brain,  the  chiasm  and  one 
medial  ganglion  of  the  corpus  mammillare  were  divided. 
[Ganser's  experiment  of  injury  to  medial  ganglion  by 
passing  a  forceps  through  the  foramen  opticum  in  a  kitten 
also  afforded  a  similar  demonstration.]  The  study  of  trans- 
sections  from  these  two  cases  showed  the  following  results  in 
parts  caudad  of  the  injured  ganglion.  There  was  no  trace 
of  the  fasc.  ad  tegmentum  on  the  side  of  the  injury,  and  this 
atrophy  could  easily  be  traced  as  far  back  as  a  point  a  little 
caudad  of  N.  iv,  ventrad  of  the  fasc.  long.  post.  The\  on 
the  normal  side  is  a  beautiful  well-defined  cell-group,  of 
which  there  is  no  trace  on  the  side  of  the  absent  fasciculus. 
Both  in  the  cat  and  rabbit  the  demonstration  of  this  new 
ganglion  was  most  conclusive. 

Now  that  the  terminal  cell-group  is  known  it  is  easy,  in 
horizontal  trans-sections  from  normal  brains,  to  trace  the 
fasc.  ad  tegmentum  all  the  way  from  its  origin  to  its  ter- 
mination. 

Observing  more  closely  the  mode  of  origin  of  the  (con- 
joined) fasc.  ad  tegmentum  and  the  fasc.  Vicq  D'  Azyr,  by 
means  of  numerous  series  of  sections,  von  Gudden  has 
recently  discovered  that  the  medial  ganglion  of  the 
corpus  mammillare  is  composed  of  two  distinct  cell-groups 
or  nuclei :  a  dorso-frontal  nucleus  which  gives  origin  to  the 
fasc.  ad  tegmentum,  and  a  ventro-caudal  mass  from  which 
springs  the  fasc.  Vicq  D'  Azyr.  This  constitutes  an  addi- 
tion to  our  knowledge  of  the  corpus  mammillare,  as  stated 
on  p.**fl[i)n 

I  propose  the  term  fasciculus  ad  tegmentum  for  the 
German  noun  Hanbenbiindel.  This  has  Prof.  Gudden's 
approval. 

XVI. — Corpus  restiforme  and  Deiters'  nucleus. 

Dr.  C.  von  Monakow,  assistant  physician  of  the  asylum  of 


GUDDEN'S  A  TROPH  Y  ME THOD.  2%  1 

St.  Pirminsberg,  in  Pfafers,  near  R(|gatz,  has  carried  on  a  /  (^/ 
number  of  most  interesting  researches  by  Gudden's  method.  ^ 
He  has  more  especially  occupied  himself  with  the  cortex 
cerebri  and  basal  ganglia,  a  field  not  specially  entered  upon 
by  Gudden.  He  also  made  one  experiment  upon  more 
peripheral  parts/  which  it  is  best  to  analyze  immediately 
after  Gudden's  studies. 

Dr.  Monakow  gives  an  historical  account  of  Deiters' 
nucleus,  or  the  so-called  external  acoustic  nucleus. 

ExPT. — In  a  newly-born  rabbit,  left  hemi-section  of  the  spinal 
cord,  just  below  the  decussation. 

Physiological  results  :  Complete  left  hemiplegia  with  nearly 
complete  recovery  later.  At  first  little  reaction  to  needle-pricks 
on  both  sides  of  body,  but  later  was  more  marked  (though  incom- 
plete) on  the  left  side.     State  of  face  not  specially  stated. 

Autopsy  in  six  months. 

Gross  changes  :  Hemi-section  not  quite  complete  ;  a  part,  inner 
half,  of  fasciculus  gracilis  (GoU's  column)  and  a  small  part  of  the 
anterior  column  remain.  Evident  ascending  degeneration  in 
medulla.  Left  side  of  cord  smaller  caudad  of  section.  Left 
vermis  superior  cerebelli  flatter. 

Microscopic  examination  of  sections  as  far  frontad  as  thalamus. 

{a)  Changes  frontad  of  injury  :  (i)  Complete  atrophy  of  fascicu- 
lus cuneatus  and  its  nucleus  ;  (2)  partial  atrophy  of  fasciculus 
gracilis  and  its  nucleus  ;  (3)  complete  atrophy  of  fasciculus  ad 
cerebellum  ;  (4)  corpus  restiforme  reduced  one  half,  atrophied, 
chiefly  in  its  medial  part  ;  (5)  the  atrophy  of  the  nucleus  of  the 
fasc.  cuneatus  is  by  far  more  marked  in  its  lateral  mass,  which  can 
be  traced  to  the  caudal  level  of  N.  viii  roots  (the  medial  nucleus  is 
reduced  one  third  without  evident  histological  changes) ;  (6)  the 
inner  division  of  the  processus  ad  medullam  (or  ascending  N.  viii 
of  Roller)  is  but  slightly  altered — at  level  of  true  N.  viii  roots  it  is 
smaller  on  the  operated  side,  because  of  absence  of  fibres  coming 
to  it  horizontally  from  corpus  restiforme  ;  (7)  at  this  level  the 
large  cells  of  Deiters'  nucleus  are  nearly  all  lost  on  the  same  side 
as  the  injury,  more  especially  in  its  latero-dorsal  aspect — this 
atrophy  blends  with  that  of  the  adjacent  corpus  restiforme — the 

'  Monakow,  Experimenteller  Beitrag  zur  Kenntniss  des  Corpus  Restiforme, 
des  "  ausseren  Acusticuskerns,"  und  deren  Beziehungen  zum  Riickenmark. — 
WestphaVs  Archiv,  Bd.  xiv,  Hft.  i. 


26  E.  C.  SEGUIN. 

acoustic  root-fibres  which  apparently  arise  from  this  nucleus  are 
seen  perfectly  intact  in  the  wasted  nucleus — all  these  roots  are 
normal  and  equal  on  the  two  sides  ;  (8)  in  the  cerebellum  the 
atrophy  can  be  indistinctly  traced  into  the  vermis  superior, 
whose  cortex  and  medulla  are  certainly  less  developed  than 
on  the  healthy  side  ;  (9)  the  left  nucleus  lateralis  is  almost 
wholly  atrophied  {vide  ^  vi,  on  origin  of  processus  ad  medul- 
1am)  ;  (10)  the  left  formatio  reticularis  in  its  lateral  part  is 
generally  reduced  and  poorer  in  cells,  a  condition  which  can  be 
traced  as  far  frontad  as  the  lobus  opticus  ;  (11)  the  pyramid  op- 
posite the  injury  is  slightly  smaller,  but  after  a  short  distance 
frontad  this  atrophy  ceases  ;  (12)  the  prolongation  of  the  lemnis- 
cus {Schleifj^  in  the  medulla  is  slightly  atrophied  on  the  same  side 
as  the  injury.  No  changes  in  lobi  optici  or  beyond  ;  these  were 
particularly  searched  for,  as  Monakow's  principal  idea  in  making 
the  experiment  was  to  trace  an  ascending  atrophy  to  the  brain. 

{b)  Changes  caudad  of  the  injury  :  Complete  atrophy  of 
pyramid  below  hemi-section,  on  same  side  of  course. 

The  perfectly  normal  parts  of  medulla  are  the  medial  part  of 
formatio  reticularis,  the  fasc.  long.  post,  (continuation  of  anterior 
column  ?),  the  upper  olives,  and  all  the  nerve  nuclei  and  roots. 
The  lower  olive  on  the  operated  side  is  a  trifle  smaller  on  the 
operated  side,  and  the  same  is  true  of  the  ascending  root  of  N.  v, 
but  the  word  atrophy  can  hardly  be  applied. 

Conclusions:  i.  That  the  processus  ad  medullam  {vide  ^ 
vi)  is  made  up  of  several  bundles:  of  the  processus  ad  cere- 
bellum {Kleinhirnseitensirangbahn),  fibrae  arcuatae,  fibres 
from  both  olives  and  the  formatio  reticularis,  and  largely  in 
its  medial  portion  of  fibres  derived  from  the  fasciculus 
cuneatus  through  its  lateral  nucleus. 

2.  This  last  portion  of  the  atrophied  corpus  restiforme 
can  be  traced  to  a  connection  with  the  large  cells  of  Deiters' 
nucleus. 

3.  Deiters'  nucleus  is  certainly  not  connected  with  the 
acoustic  nerve. 

4.  The  atrophic   fasciculus  ad  cerebellum   is   in   relation 
with  the  caudal  part  of  the  vermis  superior  (compare  p.  -'"'gQ     /  ^ 
on  connection  of  processus  ad  cerebrum,  with  frontal  party     / 
of  vermis,  as  shown  by  Forel). 


GUDDEN  'S  A  TROPH  Y  ME  THOD.  27 

The  most  important  result  of  this  experiment  is  that 
concerning  the  relations  of  Deiters'  nucleus.  With  singular 
unanimity  it  is  considered  by  anatomists  as  the  outer 
acoustic  nucleus,  because  they  have  traced  root-fibres  of 
N,  viii  into  it.  So  recent  an  authority  as  Spitzka'  not  only 
admits  it  as  a  nucleus  of  N.  viii,  but  declines  to  consider 
the  usual  division  into  an  internal  and  external  nucleus.  If 
any  anatomist  could  see,  as  I  have  seen,  the  N.  viii  fibres 
absolutely  normal  in  the  area  of  Deiters'  nucleus  while 
almost  all  the  cells  were  absent,  he  would  begin  to  reflect 
on  the  uncertainty  of  the  simple  study  of  normal  sections, 
however  carefully  or  conscientiously  carried  out.  The  an- 
nals of  encephalic  anatomy  are  replete  with  the  errors  due 
to  exclusive  devotion  to  the  Rolando-Stilling  method,  and 
it  is  high  time  that  its  delusive  teachings  be  corrected  by 
the  other  special  methods  of  research. 

XVII . — Relation  of  cortex  cerebri  to  adjacent  parts. 
The  most  important  researches  of  Dr.  von  Monakow, 
those  which  are  in  all  respects  his  own,  and  which,  if  con- 
firmed, will  add  greatly  to  our  comprehension  of  cerebral 
architecture  and  physiology,  are  those  upon  the  relations 
between  cortical  areas  and  portions  of  the  thalamus,  the 
corpora  geniculata,  and  the  lobus  opticus.  A  portion  of 
his  experiments  have  already  appeared  in  print,'^  and  two 
other  contributions  were  made  this  year  to  the  German  and 
the  Swiss  Science  Congresses  respectively.  He  was  led  to  un- 
dertake these  researches  partly  by  Munk's  physiological 
experiments,  and  partly  by  the  fact,  noted  several  times  by 
Gudden,  that  after  removal  of  one  hemisphere  in  the  rabbit, 

'"Contributions  to  Encephalic  Anatomy,"  chapter  i,  appendix  note  42. — 
youmal  of  Nervous  and  Mental  Disease,  April,  1 880. 

'  Ueber  einige  durch  Extirpation  circumscriptar  Hirnrindenregionen  bedingte 
Entwickelungshemmungen  des  Kaninchengehirns. — Arch.  f.  Psychiatric,  Bd. 
xii,  Heft  I. 

Weitere  Mittheilungen  liber  durch  Extirpation  circumscriptar  Hirnrinden- 
region  bedingte   Entwickelungshemmungen  des  Kaninchen. — Idem,  Heft  3. 


28  E.  C.  SEGUIN. 

the  thalamus  of  the  same  side  was  smaller.  He  also  ad- 
mits that  Luys  has  for  some  time  taught  that  definite  re- 
gions of  the  cortex  stood  in  relation  to  definite  portions  or 
nuclei  of  the  thalamus,  but  this  from  pure  theory. 

After  a  few  experiments  on  kittens,  he  was  obliged,  be- 
cause of  great  mortality,  to  use  rabbits,  which  he  did  with 
regret,  because  of  their  slight  intelligence  (compare  Gudden 
and  Ganser,  whose  rabbits  seemed  normal  after  removal  of 
one  hemisphere). 

ExPT.  I. — A  portion  of  cortex  and  white  substance  of  right  hemi- 
sphere was  removed  from  the  parietal  gyrus  near  the  longi- 
tudinal fissure.  This  region  M.  considers  to  be  just  caudad  of 
Ferrier's  and  Ftirstner's  area  No.  6  (see  fig.  i)  ;  about  equivalent 
to  Hitzig's  No.  I  area  in  dogs  and  monkeys  ;  and  also  to  Munk's 
centre  for  the  leg.  Caudad  and  laterad  of  extirpated  region  are 
Munk's  region  for  the  sensibility  of  the  eye,  and  further  his  visual 
sphere.     The  extirpated  zone  is  marked  a  in  fig.  i. 

Results  :  The  nucleus  externus  of  right  thalamus  is  totally  atro- 
phied. Right  corpus  geniculatum  laterale  much  atrophied,  chiefly  in 
its  caudal  portion.  Right  trapezium,  pyramid,  and  lateral  lemniscus 
a  little  smaller  than  their  homologues.  A  part  of  the  internal  cap- 
sule in  relation  with  the  wound  is  atrophied.  The  lateral  part  of 
the  crus  cerebri  is  small,  and  the  formatio  reticularis  reduced. 

ExpT.  2. — Removal  of  a  portion  of  left  occipital  lobe  (A.  in  fig. 
i).  Considers  spot  injured  as  equivalent  to  Ferrier's  and  Fiirst- 
ner's  centre  No.  9,  and  to  Munk's  area  A,  the  visual  sphere  of  the 
dog. 

Results  :  Slight  atrophy  of  medullary  substance  near  cicatrix, 
of  caudal  part  of  left  internal  capsule  ;  great  atrophy  of  left  corpus 
geniculatum  laterale  and  of  tractus  opticus,  of  left  tractus  pedun- 
cularis  transversus,  of  the  outer  part  of  the  nucleus  externus  of  the 
thalamus.  The  left  lobus  opticus  is  slightly  flattened  ;  the  right 
optic  nerve  a  little  smaller  than  its  fellow. 

Conclusions:  The  atrophy  extended  from  the  visual 
sphere  to  the  corpus  geniculatum  laterale  and  slightly  to 
the  rest  of  the  optic  apparatus  ;  it  was  in  inverse  degree 
to  what  follows  enucleation  of  the  eyeball.  The  corpus 
geniculatum  laterale  is,  therefore,    a   centre   for  vision    in 


GUDDEN  'S  A  TROPHY  METHOD. 


29 


association  with  the  cortical  centre ;  the  outer  part  of  the 
nucleus  externus  which  the  author  considers  equivalent  to 
the  pulvinar,'  is  also  a  part  of  the  optic  apparatus. 


V  £ 


The  second  article  contains  the  following  numerous  ex- 
periments : 

'  Forel  has  shown  that  the  lower  mammals  have  no  true  pulvinar. 

Monakow  adds  some  remarks  on  the  nomenclature  of  the  nuclei  of  the  thala- 
mus, and  follows  Ganser's  (Gehirn  der  Maulwurfs,  Morphol.  Jahrbuch,  Bd. 
vii,  p.  711)  arrangement,  into  nucleus  anterior  (tuberculum  anterius),  nucleus 
internus,  nucleus  externus,  and  nucleus  posterior. 

^  Explanation  of  cuts  in  the  original  articles. 

Fig.  I. — Right  hemisphere  slightly  modified  from  Monakow. 

A.  Zone  of  corp.  gen.  ext. 

B.  Zone  of  corp.  gen.  int. 

a.  Zone  of  optic  thalamus. 

b.  Zone  of  stratum  reticulare. 
d.  Zone  d. 

^andy.   Zone  of  nucleus  internus. 

On  the  left  hemisphere  are  placed  the  motor  centres  of  Ferrier,  as  depicted  in 
Fiirstner's  article,    WestphaVs  Archiv,  vol.  vi,  p.  725. 

1.  Raising  of  upper  lip  ;  rotation  of  head  to  right. 

2.  Drawing  of  mouth  to  right  ;  masticatory  movements  on  right  ;  drawing  of 
head  to  right. 

3.  The  same. 

4.  Raising  the  right  shoulder  ;  extending  the  toes. 

5.  Retraction  and  adduction  of  the  right  paw  ;  extension  of  toes. 

6.  Epileptic  seizure. 

7.  Masticatory  movements  with  the  right  upper  lip  and  jaws  ;  drawing  of 
the  head  toward  the  left. 

8.  Shutting  the  eyes. 

9.  The  same. 
10.  Indefinite. 

Fig.  2. — Profile  view  of  right  hemisphere  of  figure  I. 


30  E.  C.  SEGUIN. 

ExPT.  I. — Removal  of  zone  b,  fig.  i.  Results  :  Atrophy  of  part 
of  internal  capsule  (its  third  fifth  about),  extending  from  the 
wound  centrally  ;  of  nervous  tissue  lateradof  the  nucleus  anterior 
of  the  thalamus  (not  atrophied).  A  slight  atrophy  of  the  corpus 
geniculatum  laterale  M.  thinks  is  due  to  encroachment  of  lesion 
upon  zone  a.  The  lateral  part  of  the  crus  cerebri  is  slightly  re- 
duced in  size.  Considers  the  part  most  atrophied  in  this  experi- 
ment, the  lateral  adjunct  to  the  nucleus  anterius  as  the  stratum 
reticulare  (frontal  part  of  Gitterschichi).  Zone  b  is  therefore  the 
centre  for  the  stratum  reticulare. 

ExPT.  2. — Extirpation  of  zone  B.  This  area  occupies  the 
greater  part  of  the  temporal  lobe,  and  corresponds  with  Munk's 
auditory  sphere  B  in  dogs  and  monkeys.  Results  :  Atrophy  of 
connected  fasciculus  of  corona  radiata  and  internal  capsule 
(caudo-ventral  part),  and  of  the  corpus  geniculatum  mediale. 
There  is  also  slight  atrophy  of  the  caudal  part  of  the  stratum 
reticulare  [Gitterschicht).  No  changes  could  be  detected  in  the 
acoustic  nerve  and  its  nucleus. 

Conclusion  :  Zone  B  is  the  centre  for  the  corpus  genicu- 
latum mediale.  Query:  Is  the  corp.  gen.  med.  a  primary 
centre  for  hearing  as  the  corp.  gen.  lat.  is  for  vision  ? 

ExPT.  3. — Extirpation  of  extreme  frontal  end  of  hemisphere 
/  and  a  part  of  e  in  fig.  i.  Results  :  Atrophy  of  basal  part  of  cap- 
sula  interna,  without  and  within  the  corpus  striatum,  and  of  a  part 
of  the  nucleus  internus.  Corpus  striatum  preserved.  Pyramidal 
tract  partly  atrophied. 

ExpT.  4. — Removal  of  zone  d,  including  some  of  b.  Results  : 
Atrophy  of  corresponding  part  of  internal  capsule,  and  of  caudal 
part  of  stratum  reticulare. 

ExPT.  5. — Extirpation  of  area  including  c,  d,  e.  These  zones 
are  frontad  of  a  and  b,  and  include  nearly  all  the  motor  centres  of 
Ferrier  and  Furstner  :  its  medial  part  corresponds  to  the  para- 
central lobule.  Results  :  Atrophy  of  dependent  fasciculi  of  in- 
ternal capsule,  without  and  within  the  corpus  striatum  (which  is 
normal)  ;  atrophy  of  tuberculum  anterius  (nucleus  anterius)  to 
one  half  its  normal  size,  an  atrophy  equally  distributed  in  its 
two  cell-groups.  Thence  the  atrophy  can  be  followed  in  two 
paths,  separated  by  normal  fibres  coming  from  other  parts  of  the 
brain  :  {a)  The  ventral  atrophy  involves  the  pyramidal  tract 
(medial  part  of  crus  cerebri)  ;  the  corresponding  pyramid  is  al- 


G  UDDEN  'S  ATR  OPH  V  ME  THOD.  3  I 

most  totally  atrophied,  and  the  opposite  half  of  the  spinal  cord 
contains  the  well-known  crossed  pyramidal  atrophy.  The  corpus 
Luysii  and  the  substantia  nigra  on  the  side  of  the  injury  are  re- 
duced in  volume.  {J))  The  dorsal  atrophy  expands  into  the  area 
made  up  partly  by  the  stratum  reticulare,  and  by  the  laminae 
medullares  ext.  The  nucleus  internus  is  slightly  atrophied.  The 
fasciculus  Vicq  D'  Azyr  is  small,  but  not  reduced  in  a  degree  cor- 
responding with  the  atrophy  of  the  nucleus  anterius,  Still  an- 
other atrophy  is  produced  by  this  operation,  viz.:  that  of  a  longi- 
tudinal fasciculus  in  the  white  substance  of  the  hemisphere,  in  its 
dorsal  part,  extending  to  the  occipital  lobe  (fasciculus  longitudi- 
nalis  superior).     Areas  c,  <?,/"  constitute  a  pyramidal  zone. 

Monakow  also  extirpated  five  smaller  areas  in  a,  and  separately 
the  areas  c,  d,  e.  The  results  agreed  with  those  obtained  by  ex- 
periments detailed  above.  Altogether  more  than  fifty  experiments 
were  made. 

Summary  :  If  we  associat^the  cortical  zones  with  those 
central  nuclei  which  were  most  atrophied  by  their  extirpa- 
tion, we  have  the  following  list  : 

Zone  A,  or  visual  sphere,  is  related  to  the  corpus  genicu- 
latum  laterale. 

Zone  a  is  related  to  the  nucleus  externus. 

Zone  b  is  related  to  the  stratum  reticulare. 

Zone  B  is  related  to  the  corpus  geniculatum  mediale. 

Zones  c,  d,  e  are  related  to  the  nucleus  anterior  and 
nucleus  internus. 

Zones  c,  e,  f  are  related  to  the  pyramidal  tract. 

It  is  observable  that  the  nucleus  posterior  does  not  suffer 
in  any  of  these  experiments :  very  probably  it  is  connected 
with  strictly  basal  parts  of  the  cortex. 

Monakow  believes,  in  consequence  of  these  experiments, 
that  each  cortical  area  or  zone  is  connected  with  more 
than  one  path  or  tract. 

That  the  various  nuclei  of  the  thalamus  as  well  as  the 
corpora  geniculata  stand  in  definite  relations  to  circum- 
scribed cortical  areas. 

That  the  corpora  geniculata  medialis  et  lateralis  are  ana- 


32  E.  C.  SEGUIN. 

loeues  of  the  nuclei  of  the  thalamus  and  should  be  con- 
sidered  as  associated  with  them. 

XVI IT. — Connections  of  the  cortical  visual  area  with  the  optic 

apparatus. 

ExPT. '  I. — In  a  newly-born  kitten  removal  of  a  large  part 
of  the  parietal  cortex  and  the  subjacent  white  substance  on  one 
side.  Autopsy  in  six  months.  Results  :  Sections  frontad  of 
wound  show  great  atrophy  of  cortex  of  motor  gyri  and  of  the  un- 
derlying white  substance  on  the  same  side  as  the  injury.  Micro- 
scopic examination  shows  that  the  atrophy  bears  chiefly  upon  the 
third  layer  of  cells  in  the  cortex,  that  containing  the  larger  gang- 
lion cells  (giant-cells  of  Betz)  ;  these  are  entirely  absent.  Sec- 
tion in  the  injured  region  ;  the  corpus  striatum  is  normal,  but  the 
fasciculi  of  the  internal  capsule  which  normally  traverse  it  are 
absent,^  except  the  ventral  bundle  derived  from  the  lobus  olfac- 
torius.  The  optic  nerve  of  the  same  side  is  smaller  (its  trans- 
verse diameter  is  less)  than  its  fellow  ;  this  being  due,  in  Mona- 
kow's  opinion,  to  absence  (atrophy)  of  the  fasciculus  lateralis, 
which  has  a  connection  with  the  cortical  visual  area  (encroached 
upon  by  the  wound).  Further  caudad  the  tractus  opticus  is 
smaller  on  the  operated  side  ;  the  tuberculum  anterius  (nucleus 
anterior)  of  the  thalamus  is  wholly  atrophied.  The  commissura 
anterior  and  the  temporal  lobe  are  normal.  The  nucleus  externus 
thalami  is  almost  wholly  atrophied,  while  the  nucleus  internus  is 
preserved.  The  part  dorsad  of  the  corpus  geniculatum  lat., 
which  M.  holds  to  be  the  equivalent  of  the  human  pulvinar,  is 
fairly  preserved.  The  corp.  genie,  lat.  itself  is  somewhat  re- 
duced, but  the  mediale  is  normal.  The  lobus  opticus  on  the  in- 
jured side  is  smaller  than  its  fellow,  having  suffered  atrophy  in 
its  middle  medullary  layer.  The  medial  part  of  the  crus  cerebri 
is  much  atrophied,  and  the  lemniscus  less  developed  on  the  in- 
jured side.  The  fasc.  Vicq  d'Azyr  and  medial  ganglion  of  the 
corpus  mammillare  are  partly  atrophied.  In  the  tegmentum 
there  is  absence  of  the  pyramidal  tract  and  diminution  of  the 
lemniscus.  In  the  caudal  part  of  the  pons  there  isno  pyramid  on 
the  side  of  injury,  but  the  slight  atrophy  of  the  lemniscus  gradu- 
ally ceases. 

'  Experimentelle  Untersuchungen  iiber  umschriebene  Hirniindenatrophien. 
Vortrag  gehalten  an  der  56  Versammlung  Deutscher  Naturforscher  und  Aerzte. 
Freiburg,  Sept.,    1883. 

*  Von  Gudden  obtained  a  similar  result  in  his  experiment  of  removal  of  the 
motor  gyri,  vide  p^ 


GUDDEN'S  A  TROPH  Y  ME  THOD.  3 3 

ExPT.'  2. — In  a  newly-born  rabbit,  a  simple  oblique  stabbing 
wound  was  made  with  a  narrow  knife  in  the  temporal  lobe,  in  a 
medio-ventrad  direction.  Autopsy  in  three  and  a  half  weeks. 
It  was  found  that  the  caudal  part  of  the  internal  capsule  (Grati- 
olet's  optic  fasciculus),  its  connection  with  the  corpus  geniculatum 
mediale,  and  the  tractus  opticus,  had  been  divided  ;  the  crus 
cerebri  very  slightly  injured. 

Results :  Sections  through  the  brain  frontad  of  the  injury 
showed  the  cortex  normal,  but  its  internal  capsule  less  developed  ; 
caudad  of  the  injury,  in  the  occipital  lobe  there  is  marked  atrophy 
of  the  cortex  and  white  substance,  due  to  section  of  the  internal 
capsule.  There  is  complete  atrophy  of  the  corpus  geniculatum 
laterale  (greater  than  can  be  accounted  for  by  section  of  the 
tractus  opticus).  The  lobus  opticus  on  the  same  side  as  the  injury 
is  distinctly  smaller.  The  corp.  genie,  mediale  is  completely 
atrophied  from  section  of  the  fibres  connecting  it  with  the  internal 
capsule.  The  various  nuclei  of  the  thalamus  are  normal.  Micro- 
scopic examination  of  the  atrophied  occipital  cortex  showed  that 
the  atrophy  affected  mainly  the  third  layer,  or  layer  of  large 
ganglion  cells  ;  they  were  entirely  absent.  The  cells  of  the  fifth 
layer  were  slightly  reduced.  In  the  small  lobus  opticus  it  is  seen 
that  the  atrophy  bears  chiefly  upon  the  superficial  medullary 
layer,  whose  cells  are  fewer  and  smaller.  After  removal  of  the 
visual  area  alone  (B  in  fig.  i),  the  atrophy  of  the  lobus  opticus  is 
not  of  these  cells,  but  is  most  marked  in  the  middle  medullary 
layer.  In  the  above-detailed  experiment  there  is  also  some 
atrophy  of  this  layer,  because  a  part  of  the  optic  fasciculus  going 
to  the  cortex  was  injured.  The  atrophy  of  the  superficial  medul- 
lary layer  is,  however,  much  greater  than  after  enucleation  of  one 
eyeball. 

The  results  of  these  experiments^  Mo7iakow  s  first  and  second 
set  of  experiments  upon  the  relations  of  the  cortex  and  the 
thalamic  nuclei  {including  the  corpora  geniculatd). 

What  is  mo^^  important,  and  what,  if  confirmed,  will 
form  an  epoch  in  this  department  of  experimental  physi- 
ology, is  the  production  of  an  ascending  (centripetal) 
atrophy  of  the  cortex  by  section  of  fasciculi  of  the  internal 

'  Ueber  die  Ursprungscentren  des  Nervus  Opticus,  iind  deren  Beziehungen 
zur  Grosshirnrinde.  Vortrag  gehalten  an  der  66  Versammlung  der  Schweizer- 
ischen  Naturforschenden  Gesellschaft,  Zurich,  August,  1883. 


34  E-  C.  SEGUIN. 

capsule.  It  will  be  remembered  that  both  Gudden  and 
Monakow  (see  corpus  restiforme)  have  shown  that  after 
section  of  the  pyramidal  tract  low  down  (caudad)  there 
was  no  ascending  (centripetal)  degeneration,  or  at  most 
only  in  a  very  slight  degree  for  a  millimetre  or  two. 
But  in  both  the  last  experiments  section  of  the  internal 
capsule  (in  expt.  i  its  frontal  division,  in  expt.  2  its 
occipital  division)  caused  distinct  atrophy  of  the  associated 
cortical  regions,  in  which  mainly  the  third  cell-layer  (that 
of  giant-cells)  was  atrophied. 

The  first  experiment  also  corroborates  Gudden's  finding, 
that  the  corpus  striatum  has  no  corona  radiata. 

Another  important  result  (of  expt.  i)  is  the  apparent  dem- 
onstration that  there  is  a  degree  of  anatomical  continuity 
between  the  cortical  visual  area  and  the  optic  nerve  (its 
fasciculus  lateralis).  This  is  in  opposition  to  von  Gudden's 
results. 

The  general  agreement  between  the  results  of  physi- 
ologists (Munk,  Hitzig,  Ferrier,  and  others)  and  those 
of  von  Monakow  is  striking,  and  affords  supplementary 
evidence  of  their  approximate  exactness. 

Dr.  von  Monakow  has  recently  made  an  autopsy  of 
a  human  case  '  which  strongly  supports  his  and  Munk's  ex- 
periments on  the  visual  cortical  area. 

There  was  in  this  case  an  old  (probably  five  years  old,  judging 
by  the  imperfect  history  of  the  case)  yellow  patch  (softening  due  to 
blockade  of  branches  of  the  right  posterior  cerebral  artery)  in  the 
right  occipital  lobe,  more  especially  destroying  the  cuneus.  Pre- 
vious to  the  patient's  reception  in  the  asylum  he  had  had  "  imper- 
fect vision,"  which  was  explained  by  finding  homonymous  hemi- 
anopsia. In  sections,  one  can  trace,  in  the  clearest  manner,  a  band 
of  degeneration  from  the  patch  in  the  occipital  division  of  the  in- 
ternal capsule  (Gratiolet's  optic  fasciculus)  frontad  and  mediad  to 
the  corpus  geniculatum  laterale  and  pulvinar.    The  pulvinar  is  al- 

*  Unpublished. 


G  UDDEN '  S  A  TROPH  V  ME  THOD.  3  5 

most  entirely  atrophied,  and  the  corp.  genie,  lat.  largely  so  ;  its  folds 
are  absent.  The  crus  of  the  lobus  opticus  (brachium)  is  also  in 
a  state  of  secondary  degeneration  (granular  cells,  excessive  stain- 
ing by  carmine).  These  changes  border  closely  on  the  corp. 
genie,  mediale  which  is  normal,  a  fact  which  speaks  positively 
against  a  primary  disease  here  (besides  the  blood-vessels  of  this 
region  were  healthy).  The  lobi  optici  are  equal  and  present  no 
changes  to  the  naked  eye,  but  microscopic  examination  shows 
that  in  the  right  lobus  the  middle  medullary  layer  {inittleres 
Mark  of  Ganser)  contains  fewer  and  smaller  cross-cut  bundles 
of  nerve  fibres.  The  atrophy  is  about  the  same  as  in  Ganser's 
rat  B  {vide  p.  142  of  Archives  for  October).  The  lateral  and 
medial  parts  of  the  lemniscus  are  smaller  on  the  side  of  the 
lesion.  It  should  be  stated  that  further  frontad  the  lateral  part  of 
the  corp.  genie,  lat.  is  completely  atrophied,  while  its  medial  part 
is  preserved  ;  von  Monakow  is  disposed  to  conclude  that  the 
former  is  connected  with  the  cuneus,  while  the  latter  receives  its 
innervation  from  the  rest  of  the  visual  cortical  area. 

The  tractus  opticus  on  the  side  of  the  lesion  is  much  re- 
duced in  size.  Beyond  the  chiasm,  the  atrophy  is  traceable 
in  both  optic  nerves  ;  the  degenerated  part  standing  out  clearly 
marked  by  an  excess  of  carmine.  The  right  optic  nerve  exhibits 
a  patch  of  degeneration  in  its  lateral  aspect  (fasciculus  later- 
alis ;  the  left  nerve,  in  its  medial  aspect  (fasciculus  cruciatus). 

XIX. — Connections  of  the  optic  nerve  with  the  ^'■primary 
optic  centres!' ' 

ExPT.  I. — In  a  newly-born  rabbit,  one  eyeball  was  enucleated. 
Autopsy  after  one  year.  Results  :  Complete  atrophy  of  injured 
optic  nerve  ;  atrophy  of  tractus  opticus  on  the  opposite  side  of  its 
fibres  overlying  the  corp.  geniculatum  lat.  Also  atrophy  of  this 
nucleus,  more  especially  in  its  lateral  part.  Microscopic  examina- 
tion shows  that  this  atrophy  affects  the  fundamental  or  inter- 
cellular substance,  and  that  the  peculiar  globular  cells  are  about 
as  on  the  normal  side,  only  very  much  closer  together.  The  lobus 
opticus  is  somewhat  smaller  on  the  side  opposite  the  injury,  and 
microscopic  examination  shows  that  the  atrophy  involves  both 
cells  and  fibres  in  the  superficial  medullary  layer  {oberfldchliches 
Mark  of  Ganser).  No  change  in  the  cortex  cerebri.  In  consid- 
ering this  experiment  it  should  be  borne  in  mind  that  in  the  rab- 
bit the  optic  nerves  almost  totally  decussate. 

'  Unpublished. 


3^  E.  C.  SEGVIN. 

ExPT.  2, — In  a  newly-born  kitten,  one  eyeball  wa^  enucleated. 
Autopsy  in  three  months.  Results  :  Complete  atrophy  of  injured 
optic  nerve  ;  both  tractus  optici  are  smaller  than  normal,  the  one 
opposite  the  lesion  a  little  flatter  than  its  fellow.  [The  optic  dec- 
ussation in  cats  is  considered  by  M.  to  be  nearly  equal.]  Both 
corpora  genie,  lat.  are  smaller,  as  are  also  the  adjacent  regions 
equivalent  to  the  pulvinar.  The  streaks  normally  present  in  the 
Corp.  genie,  lat.  are  absent,  and  the  lateral  aspects  of  the  pulvinars 
exhibit  an  atrophic  indentation.  The  lobi  optici  are  about  equally 
reduced  in  size,  and  microscopic  examination  shows  the  atrophy 
to  bear  chiefly  upon  the  superficial  medullary  layer  (Ganser's  ober- 
fldchliches  Mark),  mostly  in  its  fibres,  but  also  somewhat  in  its 
ganglion  cells. 

I  cannot  close  this  review  without  expressing  my  appre- 
ciation of  the  courtesy  with  which  Doctor  von  Monakow 
received  me  at  St.  Pirminsberg,  and  the  pains  he  took  to 
demonstrate  all  his  preparations.  He,  as  well  as  Professor 
von  Gudden,  have  allowed  me  to  make  use  of  unpublished 
material,  and  its  appearance  in  the  Archives  OF  MEDICINE 
is  to  be  considered  as  preliminary  original  communications 
from  these  gentlemen. 


A 


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